| Title: | Statistical Tools for Filebacked Big Matrices |
|---|---|
| Description: | Easy-to-use, efficient, flexible and scalable statistical tools. Package bigstatsr provides and uses Filebacked Big Matrices via memory-mapping. It provides for instance matrix operations, Principal Component Analysis, sparse linear supervised models, utility functions and more <doi:10.1093/bioinformatics/bty185>. |
| Authors: | Florian Privé [aut, cre], Michael Blum [ths], Hugues Aschard [ths] |
| Maintainer: | Florian Privé <[email protected]> |
| License: | GPL-3 |
| Version: | 1.6.1 |
| Built: | 2024-11-08 05:30:30 UTC |
| Source: | https://github.com/privefl/bigstatsr |
Convenience function to create a function to be used as parameter fun.scaling
when you want to use your own precomputed center and scale.
as_scaling_fun(center.col, scale.col, ind.col = seq_along(center.col))as_scaling_fun(center.col, scale.col, ind.col = seq_along(center.col))
center.col |
Vector of centers corresponding to |
scale.col |
Vector of scales corresponding to |
ind.col |
Column indices for which these are provided. |
A function to be used as parameter fun.scaling.
fun.scaling <- as_scaling_fun(1:6, 2:7) fun.scaling(NULL, NULL, 1:3) # first two parameters X and ind.row are not used here fun.scaling2 <- as_scaling_fun(1:6, 2:7, ind.col = 6:1) fun.scaling2(NULL, NULL, 1:3) X <- big_attachExtdata() sc <- big_scale()(X) fun <- as_scaling_fun(center = sc$center, scale = sc$scale) obj.svd <- big_randomSVD(X, fun.scaling = fun) obj.svd2 <- big_randomSVD(X, fun.scaling = big_scale()) all.equal(obj.svd, obj.svd2)fun.scaling <- as_scaling_fun(1:6, 2:7) fun.scaling(NULL, NULL, 1:3) # first two parameters X and ind.row are not used here fun.scaling2 <- as_scaling_fun(1:6, 2:7, ind.col = 6:1) fun.scaling2(NULL, NULL, 1:3) X <- big_attachExtdata() sc <- big_scale()(X) fun <- as_scaling_fun(center = sc$center, scale = sc$scale) obj.svd <- big_randomSVD(X, fun.scaling = fun) obj.svd2 <- big_randomSVD(X, fun.scaling = big_scale()) all.equal(obj.svd, obj.svd2)
Convert a data.frame to plotly text
asPlotlyText(df)asPlotlyText(df)
df |
A data.frame |
A character vector of the length of df's number of rows.
set.seed(1) X <- big_attachExtdata() svd <- big_SVD(X, big_scale(), k = 10) p <- plot(svd, type = "scores") pop <- rep(c("POP1", "POP2", "POP3"), c(143, 167, 207)) df <- data.frame(Population = pop, Index = 1:517) plot(p2 <- p + ggplot2::aes(text = asPlotlyText(df))) ## Not run: plotly::ggplotly(p2, tooltip = "text")set.seed(1) X <- big_attachExtdata() svd <- big_SVD(X, big_scale(), k = 10) p <- plot(svd, type = "scores") pop <- rep(c("POP1", "POP2", "POP3"), c(143, 167, 207)) df <- data.frame(Population = pop, Index = 1:517) plot(p2 <- p + ggplot2::aes(text = asPlotlyText(df))) ## Not run: plotly::ggplotly(p2, tooltip = "text")
Compute the Area Under the ROC Curve (AUC) of a predictor and possibly its 95% confidence interval.
AUC(pred, target, digits = NULL) AUCBoot(pred, target, nboot = 10000, seed = NA, digits = NULL)AUC(pred, target, digits = NULL) AUCBoot(pred, target, nboot = 10000, seed = NA, digits = NULL)
pred |
Vector of predictions. |
target |
Vector of true labels (must have exactly two levels, no missing values). |
digits |
See round. Default doesn't use rounding. |
nboot |
Number of bootstrap samples used to evaluate the 95% CI.
Default is |
seed |
See set.seed. Use it for reproducibility. Default doesn't set any seed. |
Other packages provide ways to compute the AUC (see this answer). I chose to compute the AUC through its statistical definition as a probability:
Note that I consider equality between scores as a 50%-probability of one being greater than the other.
The AUC, a probability, and possibly its 2.5% and 97.5% quantiles (95% CI).
set.seed(1) AUC(c(0, 0), 0:1) # Equality of scores AUC(c(0.2, 0.1, 1), c(0, 0, 1)) # Perfect AUC x <- rnorm(100) z <- rnorm(length(x), x, abs(x)) y <- as.numeric(z > 0) print(AUC(x, y)) print(AUCBoot(x, y)) # Partial AUC pAUC <- function(pred, target, p = 0.1) { val.min <- min(target) q <- quantile(pred[target == val.min], probs = 1 - p) ind <- (target != val.min) | (pred > q) bigstatsr::AUC(pred[ind], target[ind]) * p } pAUC(x, y) pAUC(x, y, 0.2)set.seed(1) AUC(c(0, 0), 0:1) # Equality of scores AUC(c(0.2, 0.1, 1), c(0, 0, 1)) # Perfect AUC x <- rnorm(100) z <- rnorm(length(x), x, abs(x)) y <- as.numeric(z > 0) print(AUC(x, y)) print(AUCBoot(x, y)) # Partial AUC pAUC <- function(pred, target, p = 0.1) { val.min <- min(target) q <- quantile(pred[target == val.min], probs = 1 - p) ind <- (target != val.min) | (pred > q) bigstatsr::AUC(pred[ind], target[ind]) * p } pAUC(x, y) pAUC(x, y, 0.2)
A Split-Apply-Combine strategy to apply common R functions to a Filebacked Big Matrix.
big_apply( X, a.FUN, a.combine = NULL, ind = cols_along(X), ncores = 1, block.size = block_size(nrow(X), ncores), ... )big_apply( X, a.FUN, a.combine = NULL, ind = cols_along(X), ncores = 1, block.size = block_size(nrow(X), ncores), ... )
X |
An object of class FBM. |
a.FUN |
The function to be applied to each subset matrix.
It must take a Filebacked Big Matrix as first argument and
|
a.combine |
Function to combine the results with |
ind |
Initial vector of subsetting indices. Default is the vector of all column indices. |
ncores |
Number of cores used. Default doesn't use parallelism. You may use nb_cores. |
block.size |
Maximum number of columns (or rows, depending on how you
use |
... |
Extra arguments to be passed to |
This function splits indices in parts, then apply a given function to each subset matrix and finally combine the results. If parallelization is used, this function splits indices in parts for parallelization, then split again them on each core, apply a given function to each part and finally combine the results (on each cluster and then from each cluster). See also the corresponding vignette.
big_parallelize bigparallelr::split_parapply
X <- big_attachExtdata() # get the means of each column colMeans_sub <- function(X, ind) colMeans(X[, ind]) str(colmeans <- big_apply(X, a.FUN = colMeans_sub, a.combine = 'c')) # get the norms of each column colNorms_sub <- function(X, ind) sqrt(colSums(X[, ind]^2)) str(colnorms <- big_apply(X, colNorms_sub, a.combine = 'c')) # get the sums of each row # split along rows: need to change the "complete" `ind` parameter str(rowsums <- big_apply(X, a.FUN = function(X, ind) rowSums(X[ind, ]), ind = rows_along(X), a.combine = 'c', block.size = 100)) # it is usually preferred to split along columns # because matrices are stored by column. str(rowsums2 <- big_apply(X, a.FUN = function(X, ind) rowSums(X[, ind]), a.combine = 'plus'))X <- big_attachExtdata() # get the means of each column colMeans_sub <- function(X, ind) colMeans(X[, ind]) str(colmeans <- big_apply(X, a.FUN = colMeans_sub, a.combine = 'c')) # get the norms of each column colNorms_sub <- function(X, ind) sqrt(colSums(X[, ind]^2)) str(colnorms <- big_apply(X, colNorms_sub, a.combine = 'c')) # get the sums of each row # split along rows: need to change the "complete" `ind` parameter str(rowsums <- big_apply(X, a.FUN = function(X, ind) rowSums(X[ind, ]), ind = rows_along(X), a.combine = 'c', block.size = 100)) # it is usually preferred to split along columns # because matrices are stored by column. str(rowsums2 <- big_apply(X, a.FUN = function(X, ind) rowSums(X[, ind]), a.combine = 'plus'))
Standard univariate statistics for columns of a Filebacked Big Matrix.
For now, the sum and var are implemented
(the mean and sd can easily be deduced, see examples).
big_colstats(X, ind.row = rows_along(X), ind.col = cols_along(X), ncores = 1)big_colstats(X, ind.row = rows_along(X), ind.col = cols_along(X), ncores = 1)
X |
An object of class FBM. |
ind.row |
An optional vector of the row indices that are used. If not specified, all rows are used. Don't use negative indices. |
ind.col |
An optional vector of the column indices that are used. If not specified, all columns are used. Don't use negative indices. |
ncores |
Number of cores used. Default doesn't use parallelism. You may use nb_cores. |
Data.frame of two numeric vectors sum and var with the
corresponding column statistics.
set.seed(1) X <- big_attachExtdata() # Check the results str(test <- big_colstats(X)) # Only with the first 100 rows ind <- 1:100 str(test2 <- big_colstats(X, ind.row = ind)) plot(test$sum, test2$sum) abline(lm(test2$sum ~ test$sum), col = "red", lwd = 2) X.ind <- X[ind, ] all.equal(test2$sum, colSums(X.ind)) all.equal(test2$var, apply(X.ind, 2, var)) # deduce mean and sd # note that the are also implemented in big_scale() means <- test2$sum / length(ind) # if using all rows, # divide by nrow(X) instead all.equal(means, colMeans(X.ind)) sds <- sqrt(test2$var) all.equal(sds, apply(X.ind, 2, sd))set.seed(1) X <- big_attachExtdata() # Check the results str(test <- big_colstats(X)) # Only with the first 100 rows ind <- 1:100 str(test2 <- big_colstats(X, ind.row = ind)) plot(test$sum, test2$sum) abline(lm(test2$sum ~ test$sum), col = "red", lwd = 2) X.ind <- X[ind, ] all.equal(test2$sum, colSums(X.ind)) all.equal(test2$var, apply(X.ind, 2, var)) # deduce mean and sd # note that the are also implemented in big_scale() means <- test2$sum / length(ind) # if using all rows, # divide by nrow(X) instead all.equal(means, colMeans(X.ind)) sds <- sqrt(test2$var) all.equal(sds, apply(X.ind, 2, sd))
Deep copy of a Filebacked Big Matrix with possible subsetting. This should also work for any matrix-like object.
big_copy( X, ind.row = rows_along(X), ind.col = cols_along(X), type = typeof(X), backingfile = tempfile(tmpdir = getOption("FBM.dir")), block.size = block_size(length(ind.row)), is_read_only = FALSE )big_copy( X, ind.row = rows_along(X), ind.col = cols_along(X), type = typeof(X), backingfile = tempfile(tmpdir = getOption("FBM.dir")), block.size = block_size(length(ind.row)), is_read_only = FALSE )
X |
Could be any matrix-like object. |
ind.row |
An optional vector of the row indices that are used. If not specified, all rows are used. Don't use negative indices. |
ind.col |
An optional vector of the column indices that are used. If not specified, all columns are used. Don't use negative indices. |
type |
Type of the Filebacked Big Matrix (default is
|
backingfile |
Path to the file storing the FBM data on disk. An extension ".bk" will be automatically added. Default stores in the temporary directory, which you can change using global option "FBM.dir". |
block.size |
Maximum number of columns read at once. Default uses block_size. |
is_read_only |
Whether the FBM is read-only? Default is |
A copy of X as a new FBM object.
X <- FBM(10, 10, init = 1:100) X[] X2 <- big_copy(X, ind.row = 1:5) X2[] mat <- matrix(101:200, 10) X3 <- big_copy(mat, type = "double") # as_FBM() would be faster here X3[] X.code <- big_attachExtdata() class(X.code) X2.code <- big_copy(X.code) class(X2.code) all.equal(X.code[], X2.code[])X <- FBM(10, 10, init = 1:100) X[] X2 <- big_copy(X, ind.row = 1:5) X2[] mat <- matrix(101:200, 10) X3 <- big_copy(mat, type = "double") # as_FBM() would be faster here X3[] X.code <- big_attachExtdata() class(X.code) X2.code <- big_copy(X.code) class(X2.code) all.equal(X.code[], X2.code[])
Compute the (Pearson) correlation matrix of a Filebacked Big Matrix.
big_cor( X, ind.row = rows_along(X), ind.col = cols_along(X), block.size = block_size(nrow(X)), backingfile = tempfile(tmpdir = getOption("FBM.dir")) )big_cor( X, ind.row = rows_along(X), ind.col = cols_along(X), block.size = block_size(nrow(X)), backingfile = tempfile(tmpdir = getOption("FBM.dir")) )
X |
An object of class FBM. |
ind.row |
An optional vector of the row indices that are used. If not specified, all rows are used. Don't use negative indices. |
ind.col |
An optional vector of the column indices that are used. If not specified, all columns are used. Don't use negative indices. |
block.size |
Maximum number of columns read at once. Default uses block_size. |
backingfile |
Path to the file storing the FBM data on disk. An extension ".bk" will be automatically added. Default stores in the temporary directory, which you can change using global option "FBM.dir". |
A temporary FBM, with the following two attributes:
a numeric vector center of column scaling,
a numeric vector scale of column scaling.
Large matrix computations are made block-wise and won't be parallelized
in order to not have to reduce the size of these blocks. Instead, you can use
the MKL
or OpenBLAS in order to accelerate these block matrix computations.
You can control the number of cores used by these optimized matrix libraries
with bigparallelr::set_blas_ncores().
X <- FBM(13, 17, init = rnorm(221)) # Comparing with cor K <- big_cor(X) class(K) dim(K) K$backingfile true <- cor(X[]) all.equal(K[], true) # Using only half of the data n <- nrow(X) ind <- sort(sample(n, n/2)) K2 <- big_cor(X, ind.row = ind) true2 <- cor(X[ind, ]) all.equal(K2[], true2)X <- FBM(13, 17, init = rnorm(221)) # Comparing with cor K <- big_cor(X) class(K) dim(K) K$backingfile true <- cor(X[]) all.equal(K[], true) # Using only half of the data n <- nrow(X) ind <- sort(sample(n, n/2)) K2 <- big_cor(X, ind.row = ind) true2 <- cor(X[ind, ]) all.equal(K2[], true2)
Counts by columns (or rows) the number of each unique element of a
FBM.code256.
big_counts( X.code, ind.row = rows_along(X.code), ind.col = cols_along(X.code), byrow = FALSE )big_counts( X.code, ind.row = rows_along(X.code), ind.col = cols_along(X.code), byrow = FALSE )
X.code |
An object of class FBM.code256. |
ind.row |
An optional vector of the row indices that are used. If not specified, all rows are used. Don't use negative indices. |
ind.col |
An optional vector of the column indices that are used. If not specified, all columns are used. Don't use negative indices. |
byrow |
Count by rows rather than by columns?
Default is |
A matrix of counts of K x m (or n) elements, where
K is the number of unique elements of the BM.code,
n is its number of rows,
m is its number of columns.
Beware that K is up to 256. So, if you apply this on a Filebacked Big Matrix of one million columns, you will create a matrix of nearly 1GB!
X <- big_attachExtdata() class(X) # big_counts() is available for class FBM.code256 only X[1:5, 1:8] # by columns big_counts(X, ind.row = 1:5, ind.col = 1:8) # by rows big_counts(X, ind.row = 1:5, ind.col = 1:8, byrow = TRUE)X <- big_attachExtdata() class(X) # big_counts() is available for class FBM.code256 only X[1:5, 1:8] # by columns big_counts(X, ind.row = 1:5, ind.col = 1:8) # by rows big_counts(X, ind.row = 1:5, ind.col = 1:8, byrow = TRUE)
Cross-product between a Filebacked Big Matrix and a matrix.
big_cprodMat( X, A.row, ind.row = rows_along(X), ind.col = cols_along(X), ncores = 1, block.size = block_size(nrow(X), ncores), center = NULL, scale = NULL ) ## S4 method for signature 'FBM,matrix' crossprod(x, y) ## S4 method for signature 'FBM,matrix' tcrossprod(x, y) ## S4 method for signature 'matrix,FBM' crossprod(x, y) ## S4 method for signature 'matrix,FBM' tcrossprod(x, y)big_cprodMat( X, A.row, ind.row = rows_along(X), ind.col = cols_along(X), ncores = 1, block.size = block_size(nrow(X), ncores), center = NULL, scale = NULL ) ## S4 method for signature 'FBM,matrix' crossprod(x, y) ## S4 method for signature 'FBM,matrix' tcrossprod(x, y) ## S4 method for signature 'matrix,FBM' crossprod(x, y) ## S4 method for signature 'matrix,FBM' tcrossprod(x, y)
X |
An object of class FBM. |
A.row |
A matrix with |
ind.row |
An optional vector of the row indices that are used. If not specified, all rows are used. Don't use negative indices. |
ind.col |
An optional vector of the column indices that are used. If not specified, all columns are used. Don't use negative indices. |
ncores |
Number of cores used. Default doesn't use parallelism. You may use nb_cores. |
block.size |
Maximum number of columns read at once. Default uses block_size. |
center |
Vector of same length of |
scale |
Vector of same length of |
x |
A 'double' FBM or a matrix. |
y |
A 'double' FBM or a matrix. |
.
Large matrix computations are made block-wise and won't be parallelized
in order to not have to reduce the size of these blocks. Instead, you can use
the MKL
or OpenBLAS in order to accelerate these block matrix computations.
You can control the number of cores used by these optimized matrix libraries
with bigparallelr::set_blas_ncores().
X <- big_attachExtdata() n <- nrow(X) m <- ncol(X) A <- matrix(0, n, 10); A[] <- rnorm(length(A)) test <- big_cprodMat(X, A) true <- crossprod(X[], A) all.equal(test, true) X2 <- big_copy(X, type = "double") all.equal(crossprod(X2, A), true) # subsetting ind.row <- sample(n, n/2) ind.col <- sample(m, m/2) tryCatch(test2 <- big_cprodMat(X, A, ind.row, ind.col), error = function(e) print(e)) # returns an error. You need to use the subset of A: test2 <- big_cprodMat(X, A[ind.row, ], ind.row, ind.col) true2 <- crossprod(X[ind.row, ind.col], A[ind.row, ]) all.equal(test2, true2)X <- big_attachExtdata() n <- nrow(X) m <- ncol(X) A <- matrix(0, n, 10); A[] <- rnorm(length(A)) test <- big_cprodMat(X, A) true <- crossprod(X[], A) all.equal(test, true) X2 <- big_copy(X, type = "double") all.equal(crossprod(X2, A), true) # subsetting ind.row <- sample(n, n/2) ind.col <- sample(m, m/2) tryCatch(test2 <- big_cprodMat(X, A, ind.row, ind.col), error = function(e) print(e)) # returns an error. You need to use the subset of A: test2 <- big_cprodMat(X, A[ind.row, ], ind.row, ind.col) true2 <- crossprod(X[ind.row, ind.col], A[ind.row, ]) all.equal(test2, true2)
Cross-product between a Filebacked Big Matrix and a vector.
big_cprodVec( X, y.row, ind.row = rows_along(X), ind.col = cols_along(X), center = NULL, scale = NULL, ncores = 1 )big_cprodVec( X, y.row, ind.row = rows_along(X), ind.col = cols_along(X), center = NULL, scale = NULL, ncores = 1 )
X |
An object of class FBM. |
y.row |
A vector of same size as |
ind.row |
An optional vector of the row indices that are used. If not specified, all rows are used. Don't use negative indices. |
ind.col |
An optional vector of the column indices that are used. If not specified, all columns are used. Don't use negative indices. |
center |
Vector of same length of |
scale |
Vector of same length of |
ncores |
Number of cores used. Default doesn't use parallelism. You may use nb_cores. |
.
X <- big_attachExtdata() n <- nrow(X) m <- ncol(X) y <- rnorm(n) test <- big_cprodVec(X, y) # vector true <- crossprod(X[], y) # one-column matrix all.equal(test, as.numeric(true)) # subsetting ind.row <- sample(n, n/2) ind.col <- sample(m, m/2) tryCatch(test2 <- big_cprodVec(X, y, ind.row, ind.col), error = function(e) print(e)) # returns an error. You need to use the subset of y: test2 <- big_cprodVec(X, y[ind.row], ind.row, ind.col) true2 <- crossprod(X[ind.row, ind.col], y[ind.row]) all.equal(test2, as.numeric(true2))X <- big_attachExtdata() n <- nrow(X) m <- ncol(X) y <- rnorm(n) test <- big_cprodVec(X, y) # vector true <- crossprod(X[], y) # one-column matrix all.equal(test, as.numeric(true)) # subsetting ind.row <- sample(n, n/2) ind.col <- sample(m, m/2) tryCatch(test2 <- big_cprodVec(X, y, ind.row, ind.col), error = function(e) print(e)) # returns an error. You need to use the subset of y: test2 <- big_cprodVec(X, y[ind.row], ind.row, ind.col) true2 <- crossprod(X[ind.row, ind.col], y[ind.row]) all.equal(test2, as.numeric(true2))
Compute for a Filebacked Big Matrix X
after applying a particular scaling to it.
big_crossprodSelf( X, fun.scaling = big_scale(center = FALSE, scale = FALSE), ind.row = rows_along(X), ind.col = cols_along(X), block.size = block_size(nrow(X)), backingfile = tempfile(tmpdir = getOption("FBM.dir")) ) ## S4 method for signature 'FBM,missing' crossprod(x, y)big_crossprodSelf( X, fun.scaling = big_scale(center = FALSE, scale = FALSE), ind.row = rows_along(X), ind.col = cols_along(X), block.size = block_size(nrow(X)), backingfile = tempfile(tmpdir = getOption("FBM.dir")) ) ## S4 method for signature 'FBM,missing' crossprod(x, y)
X |
An object of class FBM. |
fun.scaling |
A function with parameters
Default doesn't use any scaling.
You can also provide your own |
ind.row |
An optional vector of the row indices that are used. If not specified, all rows are used. Don't use negative indices. |
ind.col |
An optional vector of the column indices that are used. If not specified, all columns are used. Don't use negative indices. |
block.size |
Maximum number of columns read at once. Default uses block_size. |
backingfile |
Path to the file storing the FBM data on disk. An extension ".bk" will be automatically added. Default stores in the temporary directory, which you can change using global option "FBM.dir". |
x |
A 'double' FBM. |
y |
Missing. |
A temporary FBM, with the following two attributes:
a numeric vector center of column scaling,
a numeric vector scale of column scaling.
Large matrix computations are made block-wise and won't be parallelized
in order to not have to reduce the size of these blocks. Instead, you can use
the MKL
or OpenBLAS in order to accelerate these block matrix computations.
You can control the number of cores used by these optimized matrix libraries
with bigparallelr::set_blas_ncores().
X <- FBM(13, 17, init = rnorm(221)) true <- crossprod(X[]) # No scaling K1 <- crossprod(X) class(K1) all.equal(K1, true) K2 <- big_crossprodSelf(X) class(K2) K2$backingfile all.equal(K2[], true) # big_crossprodSelf() provides some scaling and subsetting # Example using only half of the data: n <- nrow(X) ind <- sort(sample(n, n/2)) K3 <- big_crossprodSelf(X, fun.scaling = big_scale(), ind.row = ind) true2 <- crossprod(scale(X[ind, ])) all.equal(K3[], true2)X <- FBM(13, 17, init = rnorm(221)) true <- crossprod(X[]) # No scaling K1 <- crossprod(X) class(K1) all.equal(K1, true) K2 <- big_crossprodSelf(X) class(K2) K2$backingfile all.equal(K2[], true) # big_crossprodSelf() provides some scaling and subsetting # Example using only half of the data: n <- nrow(X) ind <- sort(sample(n, n/2)) K3 <- big_crossprodSelf(X, fun.scaling = big_scale(), ind.row = ind) true2 <- crossprod(scale(X[ind, ])) all.equal(K3[], true2)
Increment an FBM
big_increment(X, add, use_lock = FALSE)big_increment(X, add, use_lock = FALSE)
X |
An |
add |
A matrix of same dimensions as |
use_lock |
Whether to use locks when incrementing. Default is |
Returns nothing (NULL, invisibly).
X <- FBM(10, 10, init = 0) mat <- matrix(rnorm(100), 10, 10) big_increment(X, mat) all.equal(X[], mat) big_increment(X, mat) all.equal(X[], 2 * mat)X <- FBM(10, 10, init = 0) mat <- matrix(rnorm(100), 10, 10) big_increment(X, mat) all.equal(X[], mat) big_increment(X, mat) all.equal(X[], 2 * mat)
A Split-Apply-Combine strategy to parallelize the evaluation of a function.
big_parallelize( X, p.FUN, p.combine = NULL, ind = cols_along(X), ncores = nb_cores(), ... )big_parallelize( X, p.FUN, p.combine = NULL, ind = cols_along(X), ncores = nb_cores(), ... )
X |
An object of class FBM. |
p.FUN |
The function to be applied to each subset matrix.
It must take a Filebacked Big Matrix as first argument and
|
p.combine |
Function to combine the results with |
ind |
Initial vector of subsetting indices. Default is the vector of all column indices. |
ncores |
Number of cores used. Default doesn't use parallelism. You may use nb_cores. |
... |
Extra arguments to be passed to |
This function splits indices in parts, then apply a given function to each part and finally combine the results.
Return a list of ncores elements, each element being the result of
one of the cores, computed on a block. The elements of this list are then
combined with do.call(p.combine, .) if p.combined is given.
big_apply bigparallelr::split_parapply
## Not run: # CRAN is super slow when parallelism. X <- big_attachExtdata() ### Computation on all the matrix true <- big_colstats(X) big_colstats_sub <- function(X, ind) { big_colstats(X, ind.col = ind) } # 1. the computation is split along all the columns # 2. for each part the computation is done, using `big_colstats` # 3. the results (data.frames) are combined via `rbind`. test <- big_parallelize(X, p.FUN = big_colstats_sub, p.combine = 'rbind', ncores = 2) all.equal(test, true) ### Computation on a part of the matrix n <- nrow(X) m <- ncol(X) rows <- sort(sample(n, n/2)) # sort to provide some locality in accesses cols <- sort(sample(m, m/2)) # idem true2 <- big_colstats(X, ind.row = rows, ind.col = cols) big_colstats_sub2 <- function(X, ind, rows, cols) { big_colstats(X, ind.row = rows, ind.col = cols[ind]) } # This doesn't work because, by default, the computation is spread # along all columns. We must explictly specify the `ind` parameter. tryCatch(big_parallelize(X, p.FUN = big_colstats_sub2, p.combine = 'rbind', ncores = 2, rows = rows, cols = cols), error = function(e) message(e)) # This now works, using `ind = seq_along(cols)`. test2 <- big_parallelize(X, p.FUN = big_colstats_sub2, p.combine = 'rbind', ncores = 2, ind = seq_along(cols), rows = rows, cols = cols) all.equal(test2, true2) ## End(Not run)## Not run: # CRAN is super slow when parallelism. X <- big_attachExtdata() ### Computation on all the matrix true <- big_colstats(X) big_colstats_sub <- function(X, ind) { big_colstats(X, ind.col = ind) } # 1. the computation is split along all the columns # 2. for each part the computation is done, using `big_colstats` # 3. the results (data.frames) are combined via `rbind`. test <- big_parallelize(X, p.FUN = big_colstats_sub, p.combine = 'rbind', ncores = 2) all.equal(test, true) ### Computation on a part of the matrix n <- nrow(X) m <- ncol(X) rows <- sort(sample(n, n/2)) # sort to provide some locality in accesses cols <- sort(sample(m, m/2)) # idem true2 <- big_colstats(X, ind.row = rows, ind.col = cols) big_colstats_sub2 <- function(X, ind, rows, cols) { big_colstats(X, ind.row = rows, ind.col = cols[ind]) } # This doesn't work because, by default, the computation is spread # along all columns. We must explictly specify the `ind` parameter. tryCatch(big_parallelize(X, p.FUN = big_colstats_sub2, p.combine = 'rbind', ncores = 2, rows = rows, cols = cols), error = function(e) message(e)) # This now works, using `ind = seq_along(cols)`. test2 <- big_parallelize(X, p.FUN = big_colstats_sub2, p.combine = 'rbind', ncores = 2, ind = seq_along(cols), rows = rows, cols = cols) all.equal(test2, true2) ## End(Not run)
Product between a Filebacked Big Matrix and a matrix.
big_prodMat( X, A.col, ind.row = rows_along(X), ind.col = cols_along(X), ncores = 1, block.size = block_size(nrow(X), ncores), center = NULL, scale = NULL ) ## S4 method for signature 'FBM,matrix' x %*% y ## S4 method for signature 'matrix,FBM' x %*% ybig_prodMat( X, A.col, ind.row = rows_along(X), ind.col = cols_along(X), ncores = 1, block.size = block_size(nrow(X), ncores), center = NULL, scale = NULL ) ## S4 method for signature 'FBM,matrix' x %*% y ## S4 method for signature 'matrix,FBM' x %*% y
X |
An object of class FBM. |
A.col |
A matrix with |
ind.row |
An optional vector of the row indices that are used. If not specified, all rows are used. Don't use negative indices. |
ind.col |
An optional vector of the column indices that are used. If not specified, all columns are used. Don't use negative indices. |
ncores |
Number of cores used. Default doesn't use parallelism. You may use nb_cores. |
block.size |
Maximum number of columns read at once. Default uses block_size. |
center |
Vector of same length of |
scale |
Vector of same length of |
x |
A 'double' FBM or a matrix. |
y |
A 'double' FBM or a matrix. |
.
Large matrix computations are made block-wise and won't be parallelized
in order to not have to reduce the size of these blocks. Instead, you can use
the MKL
or OpenBLAS in order to accelerate these block matrix computations.
You can control the number of cores used by these optimized matrix libraries
with bigparallelr::set_blas_ncores().
X <- big_attachExtdata() n <- nrow(X) m <- ncol(X) A <- matrix(0, m, 10); A[] <- rnorm(length(A)) test <- big_prodMat(X, A) true <- X[] %*% A all.equal(test, true) X2 <- big_copy(X, type = "double") all.equal(X2 %*% A, true) # subsetting ind.row <- sample(n, n/2) ind.col <- sample(m, m/2) tryCatch(test2 <- big_prodMat(X, A, ind.row, ind.col), error = function(e) print(e)) # returns an error. You need to use the subset of A: test2 <- big_prodMat(X, A[ind.col, ], ind.row, ind.col) true2 <- X[ind.row, ind.col] %*% A[ind.col, ] all.equal(test2, true2)X <- big_attachExtdata() n <- nrow(X) m <- ncol(X) A <- matrix(0, m, 10); A[] <- rnorm(length(A)) test <- big_prodMat(X, A) true <- X[] %*% A all.equal(test, true) X2 <- big_copy(X, type = "double") all.equal(X2 %*% A, true) # subsetting ind.row <- sample(n, n/2) ind.col <- sample(m, m/2) tryCatch(test2 <- big_prodMat(X, A, ind.row, ind.col), error = function(e) print(e)) # returns an error. You need to use the subset of A: test2 <- big_prodMat(X, A[ind.col, ], ind.row, ind.col) true2 <- X[ind.row, ind.col] %*% A[ind.col, ] all.equal(test2, true2)
Product between a Filebacked Big Matrix and a vector.
big_prodVec( X, y.col, ind.row = rows_along(X), ind.col = cols_along(X), center = NULL, scale = NULL, ncores = 1 )big_prodVec( X, y.col, ind.row = rows_along(X), ind.col = cols_along(X), center = NULL, scale = NULL, ncores = 1 )
X |
An object of class FBM. |
y.col |
A vector of same size as |
ind.row |
An optional vector of the row indices that are used. If not specified, all rows are used. Don't use negative indices. |
ind.col |
An optional vector of the column indices that are used. If not specified, all columns are used. Don't use negative indices. |
center |
Vector of same length of |
scale |
Vector of same length of |
ncores |
Number of cores used. Default doesn't use parallelism. You may use nb_cores. |
.
X <- big_attachExtdata() n <- nrow(X) m <- ncol(X) y <- rnorm(m) test <- big_prodVec(X, y) # vector true <- X[] %*% y # one-column matrix all.equal(test, as.numeric(true)) # subsetting ind.row <- sample(n, n/2) ind.col <- sample(m, m/2) tryCatch(test2 <- big_prodVec(X, y, ind.row, ind.col), error = function(e) print(e)) # returns an error. You need to use the subset of y: test2 <- big_prodVec(X, y[ind.col], ind.row, ind.col) true2 <- X[ind.row, ind.col] %*% y[ind.col] all.equal(test2, as.numeric(true2))X <- big_attachExtdata() n <- nrow(X) m <- ncol(X) y <- rnorm(m) test <- big_prodVec(X, y) # vector true <- X[] %*% y # one-column matrix all.equal(test, as.numeric(true)) # subsetting ind.row <- sample(n, n/2) ind.col <- sample(m, m/2) tryCatch(test2 <- big_prodVec(X, y, ind.row, ind.col), error = function(e) print(e)) # returns an error. You need to use the subset of y: test2 <- big_prodVec(X, y[ind.col], ind.row, ind.col) true2 <- X[ind.row, ind.col] %*% y[ind.col] all.equal(test2, as.numeric(true2))
An algorithm for partial SVD (or PCA) of a Filebacked Big Matrix based on the
algorithm in RSpectra (by Yixuan Qiu and Jiali Mei).
This algorithm is linear in time in all dimensions and is very
memory-efficient. Thus, it can be used on very large big.matrices.
big_randomSVD( X, fun.scaling = big_scale(center = FALSE, scale = FALSE), ind.row = rows_along(X), ind.col = cols_along(X), k = 10, tol = 1e-04, verbose = FALSE, ncores = 1, fun.prod = big_prodVec, fun.cprod = big_cprodVec )big_randomSVD( X, fun.scaling = big_scale(center = FALSE, scale = FALSE), ind.row = rows_along(X), ind.col = cols_along(X), k = 10, tol = 1e-04, verbose = FALSE, ncores = 1, fun.prod = big_prodVec, fun.cprod = big_cprodVec )
X |
An object of class FBM. |
fun.scaling |
A function with parameters
Default doesn't use any scaling.
You can also provide your own |
ind.row |
An optional vector of the row indices that are used. If not specified, all rows are used. Don't use negative indices. |
ind.col |
An optional vector of the column indices that are used. If not specified, all columns are used. Don't use negative indices. |
k |
Number of singular vectors/values to compute. Default is |
tol |
Precision parameter of svds. Default is |
verbose |
Should some progress be printed? Default is |
ncores |
Number of cores used. Default doesn't use parallelism. You may use nb_cores. |
fun.prod |
Function that takes 6 arguments (in this order):
|
fun.cprod |
Same as |
A named list (an S3 class "big_SVD") of
d, the singular values,
u, the left singular vectors,
v, the right singular vectors,
niter, the number of the iteration of the algorithm,
nops, number of Matrix-Vector multiplications used,
center, the centering vector,
scale, the scaling vector.
Note that to obtain the Principal Components, you must use predict on the result. See examples.
The idea of using this Implicitly Restarted Arnoldi Method algorithm
comes from G. Abraham, Y. Qiu, and M. Inouye,
FlashPCA2: principal component analysis of biobank-scale genotype datasets,
bioRxiv: doi:10.1101/094714.
It proved to be faster than our implementation of the "blanczos" algorithm
in Rokhlin, V., Szlam, A., & Tygert, M. (2010).
A Randomized Algorithm for Principal Component Analysis.
SIAM Journal on Matrix Analysis and Applications, 31(3), 1100-1124.
doi:10.1137/080736417.
set.seed(1) X <- big_attachExtdata() K <- 10 # Using only half of the data for "training" n <- nrow(X) ind <- sort(sample(n, n/2)) test <- big_randomSVD(X, fun.scaling = big_scale(), ind.row = ind, k = K) str(test) pca <- prcomp(X[ind, ], center = TRUE, scale. = TRUE) # same scaling all.equal(test$center, pca$center) all.equal(test$scale, pca$scale) # use this function to predict scores class(test) scores <- predict(test) # scores and loadings are the same or opposite plot(scores, pca$x[, 1:K]) plot(test$v, pca$rotation[, 1:K]) plot(test$u) plot(test, type = "scores") # projecting on new data ind2 <- setdiff(rows_along(X), ind) scores.test2 <- predict(test, X, ind.row = ind2) scores.test3 <- predict(pca, X[-ind, ]) plot(scores.test2, scores.test3[, 1:K])set.seed(1) X <- big_attachExtdata() K <- 10 # Using only half of the data for "training" n <- nrow(X) ind <- sort(sample(n, n/2)) test <- big_randomSVD(X, fun.scaling = big_scale(), ind.row = ind, k = K) str(test) pca <- prcomp(X[ind, ], center = TRUE, scale. = TRUE) # same scaling all.equal(test$center, pca$center) all.equal(test$scale, pca$scale) # use this function to predict scores class(test) scores <- predict(test) # scores and loadings are the same or opposite plot(scores, pca$x[, 1:K]) plot(test$v, pca$rotation[, 1:K]) plot(test$u) plot(test, type = "scores") # projecting on new data ind2 <- setdiff(rows_along(X), ind) scores.test2 <- predict(test, X, ind.row = ind2) scores.test3 <- predict(pca, X[-ind, ]) plot(scores.test2, scores.test3[, 1:K])
Read a file as a Filebacked Big Matrix by using package {bigreadr}. For a mini-tutorial, please see this vignette.
big_read( file, select, filter = NULL, type = c("double", "float", "integer", "unsigned short", "unsigned char", "raw"), backingfile = drop_ext(file), ... )big_read( file, select, filter = NULL, type = c("double", "float", "integer", "unsigned short", "unsigned char", "raw"), backingfile = drop_ext(file), ... )
file |
File to read. |
select |
Indices of columns to read (sorted).
The length of |
filter |
Vector used to subset the rows of each data frame. |
type |
Type of the Filebacked Big Matrix (default is
|
backingfile |
Path to the file storing the FBM data on disk.
An extension ".bk" will be automatically added.
Default uses |
... |
Arguments passed on to
|
A Filebacked Big Matrix of type type with length(select) columns.
Some scaling functions for a Filebacked Big Matrix to be used as
the fun.scaling parameter of some functions of this package.
big_scale(center = TRUE, scale = TRUE)big_scale(center = TRUE, scale = TRUE)
center |
A logical value: whether to return means or 0s. |
scale |
A logical value: whether to return standard deviations or 1s. You can't use scale without using center. |
One could think about less common scalings, such as for example the
"y-aware" scaling which uses the inverse of betas of column-wise linear
regression as scaling. See this post for details.
It would be easy to implement it using big_colstats to get column means
and big_univLinReg to get betas (and then inverse them).
A new function that returns a data.frame of two vectors
"center" and "scale" which are of the length of ind.col.
X <- big_attachExtdata() # No scaling big_noscale <- big_scale(center = FALSE, scale = FALSE) class(big_noscale) # big_scale returns a new function str(big_noscale(X)) big_noscale2 <- big_scale(center = FALSE) str(big_noscale2(X)) # you can't scale without centering # Centering big_center <- big_scale(scale = FALSE) str(big_center(X)) # + scaling str(big_scale()(X))X <- big_attachExtdata() # No scaling big_noscale <- big_scale(center = FALSE, scale = FALSE) class(big_noscale) # big_scale returns a new function str(big_noscale(X)) big_noscale2 <- big_scale(center = FALSE) str(big_noscale2(X)) # you can't scale without centering # Centering big_center <- big_scale(scale = FALSE) str(big_center(X)) # + scaling str(big_scale()(X))
Fit lasso (or elastic-net) penalized linear regression for a Filebacked Big Matrix. Covariables can be added (/!\ penalized by default /!\).
big_spLinReg( X, y.train, ind.train = rows_along(X), ind.col = cols_along(X), covar.train = NULL, base.train = NULL, pf.X = NULL, pf.covar = NULL, alphas = 1, power_scale = 1, power_adaptive = 0, K = 10, ind.sets = NULL, nlambda = 200, nlam.min = 50, n.abort = 10, dfmax = 50000, warn = TRUE, ncores = 1, ... )big_spLinReg( X, y.train, ind.train = rows_along(X), ind.col = cols_along(X), covar.train = NULL, base.train = NULL, pf.X = NULL, pf.covar = NULL, alphas = 1, power_scale = 1, power_adaptive = 0, K = 10, ind.sets = NULL, nlambda = 200, nlam.min = 50, n.abort = 10, dfmax = 50000, warn = TRUE, ncores = 1, ... )
X |
An object of class FBM. |
y.train |
Vector of responses, corresponding to |
ind.train |
An optional vector of the row indices that are used, for the training part. If not specified, all rows are used. Don't use negative indices. |
ind.col |
An optional vector of the column indices that are used. If not specified, all columns are used. Don't use negative indices. |
covar.train |
Matrix of covariables to be added in each model to correct
for confounders (e.g. the scores of PCA), corresponding to |
base.train |
Vector of base predictions. Model will be learned starting from these predictions. This can be useful if you want to previously fit a model with large-effect variables that you don't want to penalize. |
pf.X |
A multiplicative factor for the penalty applied to each coefficient.
If supplied, |
pf.covar |
Same as |
alphas |
The elastic-net mixing parameter that controls the relative contribution from the lasso (l1) and the ridge (l2) penalty. The penalty is defined as
|
power_scale |
When using lasso (alpha = 1), penalization to apply that
is equivalent to scaling genotypes dividing by (standard deviation)^power_scale.
Default is 1 and corresponding to standard scaling. Using 0 would correspond
to using unscaled variables and using 0.5 is Pareto scaling. If you e.g. use
|
power_adaptive |
Multiplicative penalty factor to apply to variables
in the form of 1 / m_j^power_adaptive, where m_j is the marginal statistic
for variable j. Default is 0, which effectively disables this option.
If you e.g. use |
K |
Number of sets used in the Cross-Model Selection and Averaging
(CMSA) procedure. Default is |
ind.sets |
Integer vectors of values between |
nlambda |
The number of lambda values. Default is |
nlam.min |
Minimum number of lambda values to investigate. Default is |
n.abort |
Number of lambda values for which prediction on the validation
set must decrease before stopping. Default is |
dfmax |
Upper bound for the number of nonzero coefficients. Default is
|
warn |
Whether to warn if some models may not have reached a minimum.
Default is |
ncores |
Number of cores used. Default doesn't use parallelism. You may use nb_cores. |
... |
Arguments passed on to
|
This is a modified version of one function of
package biglasso.
It adds the possibility to train models with covariables and use many
types of FBM (not only double ones).
Yet, it only corresponds to screen = "SSR" (Sequential Strong Rules).
Also, to remove the choice of the lambda parameter, we introduce the Cross-Model Selection and Averaging (CMSA) procedure:
This function separates the training set in K folds (e.g. 10).
In turn,
each fold is considered as an inner validation set and the others (K - 1) folds form an inner training set,
the model is trained on the inner training set and the corresponding predictions (scores) for the inner validation set are computed,
the vector of scores which maximizes log-likelihood is determined,
the vector of coefficients corresponding to the previous vector of scores is chosen.
The K resulting vectors of coefficients are then averaged into one final
vector of coefficients.
Return an object of class big_sp_list (a list of length(alphas)
x K) that has 3 methods predict, summary and plot.
Tibshirani, R., Bien, J., Friedman, J., Hastie, T., Simon, N., Taylor, J. and Tibshirani, R. J. (2012), Strong rules for discarding predictors in lasso-type problems. Journal of the Royal Statistical Society: Series B (Statistical Methodology), 74: 245-266. doi:10.1111/j.1467-9868.2011.01004.x.
Zeng, Y., and Breheny, P. (2017). The biglasso Package: A Memory- and Computation-Efficient Solver for Lasso Model Fitting with Big Data in R. doi:10.32614/RJ-2021-001.
Privé, F., Aschard, H., and Blum, M. G.B. (2019). Efficient implementation of penalized regression for genetic risk prediction. Genetics, 212: 65-74. doi:10.1534/genetics.119.302019.
set.seed(1) # simulating some data N <- 230 M <- 730 X <- FBM(N, M, init = rnorm(N * M, sd = 5)) y <- rowSums(X[, 1:10]) + rnorm(N) covar <- matrix(rnorm(N * 3), N) ind.train <- sort(sample(nrow(X), 150)) ind.test <- setdiff(rows_along(X), ind.train) # fitting model for multiple lambdas and alphas test <- big_spLinReg(X, y[ind.train], ind.train = ind.train, covar.train = covar[ind.train, ], alphas = c(1, 0.1), K = 3, warn = FALSE) # peek at the models plot(test) summary(test, sort = TRUE) summary(test, sort = TRUE)$message # prediction for other data -> only the best alpha is used summary(test, best.only = TRUE) pred <- predict(test, X, ind.row = ind.test, covar.row = covar[ind.test, ]) plot(pred, y[ind.test], pch = 20); abline(0, 1, col = "red")set.seed(1) # simulating some data N <- 230 M <- 730 X <- FBM(N, M, init = rnorm(N * M, sd = 5)) y <- rowSums(X[, 1:10]) + rnorm(N) covar <- matrix(rnorm(N * 3), N) ind.train <- sort(sample(nrow(X), 150)) ind.test <- setdiff(rows_along(X), ind.train) # fitting model for multiple lambdas and alphas test <- big_spLinReg(X, y[ind.train], ind.train = ind.train, covar.train = covar[ind.train, ], alphas = c(1, 0.1), K = 3, warn = FALSE) # peek at the models plot(test) summary(test, sort = TRUE) summary(test, sort = TRUE)$message # prediction for other data -> only the best alpha is used summary(test, best.only = TRUE) pred <- predict(test, X, ind.row = ind.test, covar.row = covar[ind.test, ]) plot(pred, y[ind.test], pch = 20); abline(0, 1, col = "red")
Fit lasso (or elastic-net) penalized logistic regression for a Filebacked Big Matrix. Covariables can be added (/!\ penalized by default /!\).
big_spLogReg( X, y01.train, ind.train = rows_along(X), ind.col = cols_along(X), covar.train = NULL, base.train = NULL, pf.X = NULL, pf.covar = NULL, alphas = 1, power_scale = 1, power_adaptive = 0, K = 10, ind.sets = NULL, nlambda = 200, nlam.min = 50, n.abort = 10, dfmax = 50000, warn = TRUE, ncores = 1, ... )big_spLogReg( X, y01.train, ind.train = rows_along(X), ind.col = cols_along(X), covar.train = NULL, base.train = NULL, pf.X = NULL, pf.covar = NULL, alphas = 1, power_scale = 1, power_adaptive = 0, K = 10, ind.sets = NULL, nlambda = 200, nlam.min = 50, n.abort = 10, dfmax = 50000, warn = TRUE, ncores = 1, ... )
X |
An object of class FBM. |
y01.train |
Vector of responses, corresponding to |
ind.train |
An optional vector of the row indices that are used, for the training part. If not specified, all rows are used. Don't use negative indices. |
ind.col |
An optional vector of the column indices that are used. If not specified, all columns are used. Don't use negative indices. |
covar.train |
Matrix of covariables to be added in each model to correct
for confounders (e.g. the scores of PCA), corresponding to |
base.train |
Vector of base predictions. Model will be learned starting from these predictions. This can be useful if you want to previously fit a model with large-effect variables that you don't want to penalize. |
pf.X |
A multiplicative factor for the penalty applied to each coefficient.
If supplied, |
pf.covar |
Same as |
alphas |
The elastic-net mixing parameter that controls the relative contribution from the lasso (l1) and the ridge (l2) penalty. The penalty is defined as
|
power_scale |
When using lasso (alpha = 1), penalization to apply that
is equivalent to scaling genotypes dividing by (standard deviation)^power_scale.
Default is 1 and corresponding to standard scaling. Using 0 would correspond
to using unscaled variables and using 0.5 is Pareto scaling. If you e.g. use
|
power_adaptive |
Multiplicative penalty factor to apply to variables
in the form of 1 / m_j^power_adaptive, where m_j is the marginal statistic
for variable j. Default is 0, which effectively disables this option.
If you e.g. use |
K |
Number of sets used in the Cross-Model Selection and Averaging
(CMSA) procedure. Default is |
ind.sets |
Integer vectors of values between |
nlambda |
The number of lambda values. Default is |
nlam.min |
Minimum number of lambda values to investigate. Default is |
n.abort |
Number of lambda values for which prediction on the validation
set must decrease before stopping. Default is |
dfmax |
Upper bound for the number of nonzero coefficients. Default is
|
warn |
Whether to warn if some models may not have reached a minimum.
Default is |
ncores |
Number of cores used. Default doesn't use parallelism. You may use nb_cores. |
... |
Arguments passed on to
|
This is a modified version of one function of
package biglasso.
It adds the possibility to train models with covariables and use many
types of FBM (not only double ones).
Yet, it only corresponds to screen = "SSR" (Sequential Strong Rules).
Also, to remove the choice of the lambda parameter, we introduce the Cross-Model Selection and Averaging (CMSA) procedure:
This function separates the training set in K folds (e.g. 10).
In turn,
each fold is considered as an inner validation set and the others (K - 1) folds form an inner training set,
the model is trained on the inner training set and the corresponding predictions (scores) for the inner validation set are computed,
the vector of scores which maximizes log-likelihood is determined,
the vector of coefficients corresponding to the previous vector of scores is chosen.
The K resulting vectors of coefficients are then averaged into one final
vector of coefficients.
Return an object of class big_sp_list (a list of length(alphas)
x K) that has 3 methods predict, summary and plot.
Tibshirani, R., Bien, J., Friedman, J., Hastie, T., Simon, N., Taylor, J. and Tibshirani, R. J. (2012), Strong rules for discarding predictors in lasso-type problems. Journal of the Royal Statistical Society: Series B (Statistical Methodology), 74: 245-266. doi:10.1111/j.1467-9868.2011.01004.x.
Zeng, Y., and Breheny, P. (2017). The biglasso Package: A Memory- and Computation-Efficient Solver for Lasso Model Fitting with Big Data in R. doi:10.32614/RJ-2021-001.
Privé, F., Aschard, H., and Blum, M. G.B. (2019). Efficient implementation of penalized regression for genetic risk prediction. Genetics, 212: 65-74. doi:10.1534/genetics.119.302019.
set.seed(2) # simulating some data N <- 230 M <- 730 X <- FBM(N, M, init = rnorm(N * M, sd = 5)) y01 <- as.numeric((rowSums(X[, 1:10]) + 2 * rnorm(N)) > 0) covar <- matrix(rnorm(N * 3), N) ind.train <- sort(sample(nrow(X), 150)) ind.test <- setdiff(rows_along(X), ind.train) # fitting model for multiple lambdas and alphas test <- big_spLogReg(X, y01[ind.train], ind.train = ind.train, covar.train = covar[ind.train, ], alphas = c(1, 0.1), K = 3, warn = FALSE) # peek at the models plot(test) summary(test, sort = TRUE) summary(test, sort = TRUE)$message # prediction for other data -> only the best alpha is used summary(test, best.only = TRUE) pred <- predict(test, X, ind.row = ind.test, covar.row = covar[ind.test, ]) AUC(pred, y01[ind.test]) library(ggplot2) qplot(pred, fill = as.logical(y01[ind.test]), geom = "density", alpha = I(0.4)) + labs(fill = "Case?") + theme_bigstatsr() + theme(legend.position = c(0.52, 0.8))set.seed(2) # simulating some data N <- 230 M <- 730 X <- FBM(N, M, init = rnorm(N * M, sd = 5)) y01 <- as.numeric((rowSums(X[, 1:10]) + 2 * rnorm(N)) > 0) covar <- matrix(rnorm(N * 3), N) ind.train <- sort(sample(nrow(X), 150)) ind.test <- setdiff(rows_along(X), ind.train) # fitting model for multiple lambdas and alphas test <- big_spLogReg(X, y01[ind.train], ind.train = ind.train, covar.train = covar[ind.train, ], alphas = c(1, 0.1), K = 3, warn = FALSE) # peek at the models plot(test) summary(test, sort = TRUE) summary(test, sort = TRUE)$message # prediction for other data -> only the best alpha is used summary(test, best.only = TRUE) pred <- predict(test, X, ind.row = ind.test, covar.row = covar[ind.test, ]) AUC(pred, y01[ind.test]) library(ggplot2) qplot(pred, fill = as.logical(y01[ind.test]), geom = "density", alpha = I(0.4)) + labs(fill = "Case?") + theme_bigstatsr() + theme(legend.position = c(0.52, 0.8))
An algorithm for partial SVD (or PCA) of a Filebacked Big Matrix through the eigen decomposition of the covariance between variables (primal) or observations (dual). Use this algorithm only if there is one dimension that is much smaller than the other. Otherwise use big_randomSVD.
big_SVD( X, fun.scaling = big_scale(center = FALSE, scale = FALSE), ind.row = rows_along(X), ind.col = cols_along(X), k = 10, block.size = block_size(nrow(X)) )big_SVD( X, fun.scaling = big_scale(center = FALSE, scale = FALSE), ind.row = rows_along(X), ind.col = cols_along(X), k = 10, block.size = block_size(nrow(X)) )
X |
An object of class FBM. |
fun.scaling |
A function with parameters
Default doesn't use any scaling.
You can also provide your own |
ind.row |
An optional vector of the row indices that are used. If not specified, all rows are used. Don't use negative indices. |
ind.col |
An optional vector of the column indices that are used. If not specified, all columns are used. Don't use negative indices. |
k |
Number of singular vectors/values to compute. Default is |
block.size |
Maximum number of columns read at once. Default uses block_size. |
To get ,
if the number of observations is small, this function computes
and then
,
if the number of variable is small, this function computes
and then
,
if both dimensions are large, use big_randomSVD instead.
A named list (an S3 class "big_SVD") of
d, the singular values,
u, the left singular vectors,
v, the right singular vectors,
center, the centering vector,
scale, the scaling vector.
Note that to obtain the Principal Components, you must use predict on the result. See examples.
Large matrix computations are made block-wise and won't be parallelized
in order to not have to reduce the size of these blocks. Instead, you can use
the MKL
or OpenBLAS in order to accelerate these block matrix computations.
You can control the number of cores used by these optimized matrix libraries
with bigparallelr::set_blas_ncores().
set.seed(1) X <- big_attachExtdata() n <- nrow(X) # Using only half of the data ind <- sort(sample(n, n/2)) test <- big_SVD(X, fun.scaling = big_scale(), ind.row = ind) str(test) plot(test$u) pca <- prcomp(X[ind, ], center = TRUE, scale. = TRUE) # same scaling all.equal(test$center, pca$center) all.equal(test$scale, pca$scale) # scores and loadings are the same or opposite # except for last eigenvalue which is equal to 0 # due to centering of columns scores <- test$u %*% diag(test$d) class(test) scores2 <- predict(test) # use this function to predict scores all.equal(scores, scores2) dim(scores) dim(pca$x) tail(pca$sdev) plot(scores2, pca$x[, 1:ncol(scores2)]) plot(test$v[1:100, ], pca$rotation[1:100, 1:ncol(scores2)]) # projecting on new data X2 <- sweep(sweep(X[-ind, ], 2, test$center, '-'), 2, test$scale, '/') scores.test <- X2 %*% test$v ind2 <- setdiff(rows_along(X), ind) scores.test2 <- predict(test, X, ind.row = ind2) # use this all.equal(scores.test, scores.test2) scores.test3 <- predict(pca, X[-ind, ]) plot(scores.test2, scores.test3[, 1:ncol(scores.test2)])set.seed(1) X <- big_attachExtdata() n <- nrow(X) # Using only half of the data ind <- sort(sample(n, n/2)) test <- big_SVD(X, fun.scaling = big_scale(), ind.row = ind) str(test) plot(test$u) pca <- prcomp(X[ind, ], center = TRUE, scale. = TRUE) # same scaling all.equal(test$center, pca$center) all.equal(test$scale, pca$scale) # scores and loadings are the same or opposite # except for last eigenvalue which is equal to 0 # due to centering of columns scores <- test$u %*% diag(test$d) class(test) scores2 <- predict(test) # use this function to predict scores all.equal(scores, scores2) dim(scores) dim(pca$x) tail(pca$sdev) plot(scores2, pca$x[, 1:ncol(scores2)]) plot(test$v[1:100, ], pca$rotation[1:100, 1:ncol(scores2)]) # projecting on new data X2 <- sweep(sweep(X[-ind, ], 2, test$center, '-'), 2, test$scale, '/') scores.test <- X2 %*% test$v ind2 <- setdiff(rows_along(X), ind) scores.test2 <- predict(test, X, ind.row = ind2) # use this all.equal(scores.test, scores.test2) scores.test3 <- predict(pca, X[-ind, ]) plot(scores.test2, scores.test3[, 1:ncol(scores.test2)])
Compute for a Filebacked Big Matrix X
after applying a particular scaling to it.
big_tcrossprodSelf( X, fun.scaling = big_scale(center = FALSE, scale = FALSE), ind.row = rows_along(X), ind.col = cols_along(X), block.size = block_size(nrow(X)) ) ## S4 method for signature 'FBM,missing' tcrossprod(x, y)big_tcrossprodSelf( X, fun.scaling = big_scale(center = FALSE, scale = FALSE), ind.row = rows_along(X), ind.col = cols_along(X), block.size = block_size(nrow(X)) ) ## S4 method for signature 'FBM,missing' tcrossprod(x, y)
X |
An object of class FBM. |
fun.scaling |
A function with parameters
Default doesn't use any scaling.
You can also provide your own |
ind.row |
An optional vector of the row indices that are used. If not specified, all rows are used. Don't use negative indices. |
ind.col |
An optional vector of the column indices that are used. If not specified, all columns are used. Don't use negative indices. |
block.size |
Maximum number of columns read at once. Default uses block_size. |
x |
A 'double' FBM. |
y |
Missing. |
A temporary FBM, with the following two attributes:
a numeric vector center of column scaling,
a numeric vector scale of column scaling.
Large matrix computations are made block-wise and won't be parallelized
in order to not have to reduce the size of these blocks. Instead, you can use
the MKL
or OpenBLAS in order to accelerate these block matrix computations.
You can control the number of cores used by these optimized matrix libraries
with bigparallelr::set_blas_ncores().
X <- FBM(13, 17, init = rnorm(221)) true <- tcrossprod(X[]) # No scaling K1 <- tcrossprod(X) class(K1) all.equal(K1, true) K2 <- big_tcrossprodSelf(X) class(K2) K2$backingfile all.equal(K2[], true) # big_tcrossprodSelf() provides some scaling and subsetting # Example using only half of the data: n <- nrow(X) ind <- sort(sample(n, n/2)) K3 <- big_tcrossprodSelf(X, fun.scaling = big_scale(), ind.row = ind) true2 <- tcrossprod(scale(X[ind, ])) all.equal(K3[], true2)X <- FBM(13, 17, init = rnorm(221)) true <- tcrossprod(X[]) # No scaling K1 <- tcrossprod(X) class(K1) all.equal(K1, true) K2 <- big_tcrossprodSelf(X) class(K2) K2$backingfile all.equal(K2[], true) # big_tcrossprodSelf() provides some scaling and subsetting # Example using only half of the data: n <- nrow(X) ind <- sort(sample(n, n/2)) K3 <- big_tcrossprodSelf(X, fun.scaling = big_scale(), ind.row = ind) true2 <- tcrossprod(scale(X[ind, ])) all.equal(K3[], true2)
This function implements a simple cache-oblivious algorithm for the transposition of a Filebacked Big Matrix.
big_transpose(X, backingfile = tempfile(tmpdir = getOption("FBM.dir")))big_transpose(X, backingfile = tempfile(tmpdir = getOption("FBM.dir")))
X |
An object of class FBM. |
backingfile |
Path to the file storing the FBM data on disk. An extension ".bk" will be automatically added. Default stores in the temporary directory, which you can change using global option "FBM.dir". |
The new transposed FBM. Dimensions and type are automatically determined from the input FBM.
X <- FBM(6, 5, init = rnorm(30)) X[] Xt <- big_transpose(X) identical(t(X[]), Xt[])X <- FBM(6, 5, init = rnorm(30)) X[] Xt <- big_transpose(X) identical(t(X[]), Xt[])
Slopes of column-wise linear regressions of each column of a Filebacked Big Matrix, with some other associated statistics. Covariates can be added to correct for confounders.
big_univLinReg( X, y.train, ind.train = rows_along(X), ind.col = cols_along(X), covar.train = NULL, thr.eigval = 1e-04, ncores = 1 )big_univLinReg( X, y.train, ind.train = rows_along(X), ind.col = cols_along(X), covar.train = NULL, thr.eigval = 1e-04, ncores = 1 )
X |
An object of class FBM. |
y.train |
Vector of responses, corresponding to |
ind.train |
An optional vector of the row indices that are used, for the training part. If not specified, all rows are used. Don't use negative indices. |
ind.col |
An optional vector of the column indices that are used. If not specified, all columns are used. Don't use negative indices. |
covar.train |
Matrix of covariables to be added in each model to correct
for confounders (e.g. the scores of PCA), corresponding to |
thr.eigval |
Threshold to remove "insignificant" singular vectors.
Default is |
ncores |
Number of cores used. Default doesn't use parallelism. You may use nb_cores. |
A data.frame with 3 elements:
the slopes of each regression,
the standard errors of each slope,
the t-scores associated with each slope.
This is also an object of class mhtest. See methods(class = "mhtest").
set.seed(1) X <- big_attachExtdata() n <- nrow(X) y <- rnorm(n) covar <- matrix(rnorm(n * 3), n) X1 <- X[, 1] # only first column of the Filebacked Big Matrix # Without covar test <- big_univLinReg(X, y) ## New class `mhtest` class(test) attr(test, "transfo") attr(test, "predict") ## plot results plot(test) plot(test, type = "Volcano") ## To get p-values associated with the test test$p.value <- predict(test, log10 = FALSE) str(test) summary(lm(y ~ X1))$coefficients[2, ] # With all data str(big_univLinReg(X, y, covar = covar)) summary(lm(y ~ X1 + covar))$coefficients[2, ] # With only half of the data ind.train <- sort(sample(n, n/2)) str(big_univLinReg(X, y[ind.train], covar.train = covar[ind.train, ], ind.train = ind.train)) summary(lm(y ~ X1 + covar, subset = ind.train))$coefficients[2, ]set.seed(1) X <- big_attachExtdata() n <- nrow(X) y <- rnorm(n) covar <- matrix(rnorm(n * 3), n) X1 <- X[, 1] # only first column of the Filebacked Big Matrix # Without covar test <- big_univLinReg(X, y) ## New class `mhtest` class(test) attr(test, "transfo") attr(test, "predict") ## plot results plot(test) plot(test, type = "Volcano") ## To get p-values associated with the test test$p.value <- predict(test, log10 = FALSE) str(test) summary(lm(y ~ X1))$coefficients[2, ] # With all data str(big_univLinReg(X, y, covar = covar)) summary(lm(y ~ X1 + covar))$coefficients[2, ] # With only half of the data ind.train <- sort(sample(n, n/2)) str(big_univLinReg(X, y[ind.train], covar.train = covar[ind.train, ], ind.train = ind.train)) summary(lm(y ~ X1 + covar, subset = ind.train))$coefficients[2, ]
Slopes of column-wise logistic regressions of each column of a Filebacked Big Matrix, with some other associated statistics. Covariates can be added to correct for confounders.
big_univLogReg( X, y01.train, ind.train = rows_along(X), ind.col = cols_along(X), covar.train = NULL, tol = 1e-08, maxiter = 20, ncores = 1 )big_univLogReg( X, y01.train, ind.train = rows_along(X), ind.col = cols_along(X), covar.train = NULL, tol = 1e-08, maxiter = 20, ncores = 1 )
X |
An object of class FBM. |
y01.train |
Vector of responses, corresponding to |
ind.train |
An optional vector of the row indices that are used, for the training part. If not specified, all rows are used. Don't use negative indices. |
ind.col |
An optional vector of the column indices that are used. If not specified, all columns are used. Don't use negative indices. |
covar.train |
Matrix of covariables to be added in each model to correct
for confounders (e.g. the scores of PCA), corresponding to |
tol |
Relative tolerance to assess convergence of the coefficient.
Default is |
maxiter |
Maximum number of iterations before giving up.
Default is |
ncores |
Number of cores used. Default doesn't use parallelism. You may use nb_cores. |
If convergence is not reached by the main algorithm for some columns,
the corresponding niter element is set to NA and a message is given.
Then, glm is used instead for the corresponding column.
If it can't converge either, all corresponding estimations are set to NA.
A data.frame with 4 elements:
the slopes of each regression,
the standard errors of each slope,
the number of iteration for each slope. If is NA, this means that the
algorithm didn't converge, and glm was used instead.
the z-scores associated with each slope.
This is also an object of class mhtest. See methods(class = "mhtest").
set.seed(1) X <- big_attachExtdata() n <- nrow(X) y01 <- sample(0:1, size = n, replace = TRUE) covar <- matrix(rnorm(n * 3), n) X1 <- X[, 1] # only first column of the Filebacked Big Matrix # Without covar test <- big_univLogReg(X, y01) ## new class `mhtest` class(test) attr(test, "transfo") attr(test, "predict") ## plot results plot(test) plot(test, type = "Volcano") ## To get p-values associated with the test test$p.value <- predict(test, log10 = FALSE) str(test) summary(glm(y01 ~ X1, family = "binomial"))$coefficients[2, ] # With all data str(big_univLogReg(X, y01, covar.train = covar)) summary(glm(y01 ~ X1 + covar, family = "binomial"))$coefficients[2, ] # With only half of the data ind.train <- sort(sample(n, n/2)) str(big_univLogReg(X, y01[ind.train], covar.train = covar[ind.train, ], ind.train = ind.train)) summary(glm(y01 ~ X1 + covar, family = "binomial", subset = ind.train))$coefficients[2, ]set.seed(1) X <- big_attachExtdata() n <- nrow(X) y01 <- sample(0:1, size = n, replace = TRUE) covar <- matrix(rnorm(n * 3), n) X1 <- X[, 1] # only first column of the Filebacked Big Matrix # Without covar test <- big_univLogReg(X, y01) ## new class `mhtest` class(test) attr(test, "transfo") attr(test, "predict") ## plot results plot(test) plot(test, type = "Volcano") ## To get p-values associated with the test test$p.value <- predict(test, log10 = FALSE) str(test) summary(glm(y01 ~ X1, family = "binomial"))$coefficients[2, ] # With all data str(big_univLogReg(X, y01, covar.train = covar)) summary(glm(y01 ~ X1 + covar, family = "binomial"))$coefficients[2, ] # With only half of the data ind.train <- sort(sample(n, n/2)) str(big_univLogReg(X, y01[ind.train], covar.train = covar[ind.train, ], ind.train = ind.train)) summary(glm(y01 ~ X1 + covar, family = "binomial", subset = ind.train))$coefficients[2, ]
Write a file from a Filebacked Big Matrix (by parts).
big_write( X, file, every_nrow, ..., ind.row = rows_along(X), ind.col = cols_along(X), progress = FALSE )big_write( X, file, every_nrow, ..., ind.row = rows_along(X), ind.col = cols_along(X), progress = FALSE )
X |
An object of class FBM. |
file |
File to write to. |
every_nrow |
Number of rows to write at once. |
... |
Other arguments to be passed to data.table::fwrite,
except |
ind.row |
An optional vector of the row indices that are used. If not specified, all rows are used. Don't use negative indices. |
ind.col |
An optional vector of the column indices that are used. If not specified, all columns are used. Don't use negative indices. |
progress |
Show progress? Default is |
Input parameter file, invisibly.
X <- big_attachExtdata() csv <- big_write(X, tempfile(), every_nrow = 100, progress = interactive())X <- big_attachExtdata() csv <- big_write(X, tempfile(), every_nrow = 100, progress = interactive())
It determines the value of block.size such that a matrix of doubles of
size n x block.size takes less memory than
getOption("bigstatsr.block.sizeGB") GigaBytes (default is 1GB).
block_size(n, ncores = 1)block_size(n, ncores = 1)
n |
The number of rows. |
ncores |
The number of cores. |
An integer >= 1.
block_size(1e3) block_size(1e6) block_size(1e6, 6)block_size(1e3) block_size(1e6) block_size(1e6, 6)
Transform a data frame to a numeric matrix by one-hot encoding factors. The last factor value is always omitted to prevent having a singular matrix when adding a column of 1s (intercept) in models.
covar_from_df(df)covar_from_df(df)
df |
A data frame. |
A numeric matrix.
mat <- covar_from_df(iris) head(mat)mat <- covar_from_df(iris) head(mat)
A reference class for storing and accessing matrix-like data stored in files on disk. This is very similar to Filebacked Big Matrices provided by the bigmemory package (see the corresponding vignette).
Convert a matrix (or a data frame) to an FBM.
FBM( nrow, ncol, type = c("double", "float", "integer", "unsigned short", "unsigned char", "raw"), init = NULL, backingfile = tempfile(tmpdir = getOption("FBM.dir")), create_bk = TRUE, is_read_only = FALSE ) as_FBM( x, type = c("double", "float", "integer", "unsigned short", "unsigned char", "raw"), backingfile = tempfile(tmpdir = getOption("FBM.dir")), is_read_only = FALSE )FBM( nrow, ncol, type = c("double", "float", "integer", "unsigned short", "unsigned char", "raw"), init = NULL, backingfile = tempfile(tmpdir = getOption("FBM.dir")), create_bk = TRUE, is_read_only = FALSE ) as_FBM( x, type = c("double", "float", "integer", "unsigned short", "unsigned char", "raw"), backingfile = tempfile(tmpdir = getOption("FBM.dir")), is_read_only = FALSE )
nrow |
Number of rows. |
ncol |
Number of columns. |
type |
Type of the Filebacked Big Matrix (default is
|
init |
Either a single value (e.g. |
backingfile |
Path to the file storing the FBM data on disk. An extension ".bk" will be automatically added. Default stores in the temporary directory, which you can change using global option "FBM.dir". |
create_bk |
Whether to create a backingfile (the default) or use an
existing one (which should be named by the |
is_read_only |
Whether the FBM is read-only? Default is |
x |
A matrix or an data frame (2-dimensional data). |
An object of class FBM has many fields:
$address: address of the external pointer containing the underlying
C++ object for read-only mapping, to be used as a XPtr<FBM> in C++ code
$extptr: (internal) use $address instead
$address_rw: address of the external pointer containing the underlying
C++ object for read/write mapping, to be used as a XPtr<FBM_RW> in C++ code
$extptr_rw: (internal) use $address_rw instead
$nrow: number of rows
$ncol: number of columns
$type: (internal) use type_size or type_chr instead
$type_chr: FBM type as character, e.g. "double"
$type_size: size of FBM type in bytes (e.g. "double" is 8 and "float" is 4)
$backingfile or $bk: File with extension 'bk' that stores the numeric
data of the FBM
$rds: 'rds' file (that may not exist) corresponding to the 'bk' file
$is_saved: whether this object is stored in $rds?
$is_read_only: whether it is (not) allowed to modify data?
And some methods:
$save(): Save the FBM object in $rds. Returns the FBM.
add_columns(<ncol_add>): Add some columns to the FBM by appending the
backingfile with some data. Returns the FBM invisibly.
$bm(): Get this object as a filebacked.big.matrix
to be used by package {bigmemory}.
$bm.desc(): Get this object as a filebacked.big.matrix descriptor
to be used by package {bigmemory}.
$check_write_permissions(): Error if the FBM is read-only.
mat <- matrix(1:4, 2) X_from_mat <- as_FBM(mat) ## You can save this object in an .rds file to use it in another session X_from_mat$is_saved X_from_mat$save() X_from_mat$is_saved (rds <- X_from_mat$rds) ## Use big_attach() to load the FBM object in another session X_from_mat <- big_attach(rds) ## Standard accessors X <- FBM(10, 10) typeof(X) X[] <- rnorm(length(X)) X[, 1:6] X[] <- 1:100 X[, 1] X[1, ] # not recommended for large matrices X[, -1] X[, c(TRUE, FALSE)] X[cbind(1:10, 1:10)] <- NA_real_ X[] # access as standard R matrix X <- FBM(150, 5) X[] <- iris ## you can replace with a df (but factors -> integers) X2 <- as_FBM(iris) identical(X[], X2[])mat <- matrix(1:4, 2) X_from_mat <- as_FBM(mat) ## You can save this object in an .rds file to use it in another session X_from_mat$is_saved X_from_mat$save() X_from_mat$is_saved (rds <- X_from_mat$rds) ## Use big_attach() to load the FBM object in another session X_from_mat <- big_attach(rds) ## Standard accessors X <- FBM(10, 10) typeof(X) X[] <- rnorm(length(X)) X[, 1:6] X[] <- 1:100 X[, 1] X[1, ] # not recommended for large matrices X[, -1] X[, c(TRUE, FALSE)] X[cbind(1:10, 1:10)] <- NA_real_ X[] # access as standard R matrix X <- FBM(150, 5) X[] <- iris ## you can replace with a df (but factors -> integers) X2 <- as_FBM(iris) identical(X[], X2[])
Methods for the FBM class
Accessor methods for class FBM. You can use positive and negative indices,
logical indices (that are recycled) and also a matrix of indices (but only
positive ones).
Dimension and type methods for class FBM.
## S4 method for signature 'FBM,ANY,ANY,ANY' x[i, j, ..., drop = TRUE] ## S4 replacement method for signature 'FBM,ANY,ANY,ANY' x[i, j, ...] <- value ## S4 method for signature 'FBM' dim(x) ## S4 method for signature 'FBM' length(x) ## S4 method for signature 'FBM' typeof(x) ## S4 method for signature 'FBM' diag(x)## S4 method for signature 'FBM,ANY,ANY,ANY' x[i, j, ..., drop = TRUE] ## S4 replacement method for signature 'FBM,ANY,ANY,ANY' x[i, j, ...] <- value ## S4 method for signature 'FBM' dim(x) ## S4 method for signature 'FBM' length(x) ## S4 method for signature 'FBM' typeof(x) ## S4 method for signature 'FBM' diag(x)
x |
A FBM object. |
i |
A vector of indices (or nothing). You can use positive and negative indices, logical indices (that are recycled) and also a matrix of indices (but only positive ones). |
j |
A vector of indices (or nothing). You can use positive and negative indices, logical indices (that are recycled). |
... |
Not used. Just to make nargs work. |
drop |
Whether to delete the dimensions of a matrix which have one dimension equals to 1. |
value |
The values to replace. Should be of length 1 or of the same length of the subset to replace. |
A reference class for storing and accessing up to 256 arbitrary different
values using a Filebacked Big Matrix of type unsigned char. Compared to a
Filebacked Big Matrix, it adds a slot code which is used as
a lookup table of size 256.
FBM.code256( nrow, ncol, code = rep(NA_real_, 256), init = NULL, backingfile = tempfile(tmpdir = getOption("FBM.dir")), create_bk = TRUE, is_read_only = FALSE ) add_code256(x, code)FBM.code256( nrow, ncol, code = rep(NA_real_, 256), init = NULL, backingfile = tempfile(tmpdir = getOption("FBM.dir")), create_bk = TRUE, is_read_only = FALSE ) add_code256(x, code)
nrow |
Number of rows. |
ncol |
Number of columns. |
code |
A numeric vector (of length 256).
You should construct it with |
init |
Either a single value (e.g. |
backingfile |
Path to the file storing the FBM data on disk. An extension ".bk" will be automatically added. Default stores in the temporary directory, which you can change using global option "FBM.dir". |
create_bk |
Whether to create a backingfile (the default) or use an
existing one (which should be named by the |
is_read_only |
Whether the FBM is read-only? Default is |
x |
A FBM. |
X <- FBM(10, 10, type = "raw") X[] <- sample(as.raw(0:3), size = length(X), replace = TRUE) X[] # From an FBM of type 'raw' ('unsigned char') code <- rep(NA_real_, 256) code[1:3] <- c(1, 3, 5) X.code <- add_code256(X, code) X.code[] # Or directly X.code2 <- FBM.code256(10, 10, code, init = sample(as.raw(0:3), 100, TRUE)) X.code2[] # Get a new FBM.code256 object with another code (but same underlying data) X.code3 <- X.code$copy(code = rnorm(256)) all.equal(X.code$code256, code)X <- FBM(10, 10, type = "raw") X[] <- sample(as.raw(0:3), size = length(X), replace = TRUE) X[] # From an FBM of type 'raw' ('unsigned char') code <- rep(NA_real_, 256) code[1:3] <- c(1, 3, 5) X.code <- add_code256(X, code) X.code[] # Or directly X.code2 <- FBM.code256(10, 10, code, init = sample(as.raw(0:3), 100, TRUE)) X.code2[] # Get a new FBM.code256 object with another code (but same underlying data) X.code3 <- X.code$copy(code = rnorm(256)) all.equal(X.code$code256, code)
Combine sets of coefficients
get_beta(betas, method = c("geometric-median", "mean-wise", "median-wise"))get_beta(betas, method = c("geometric-median", "mean-wise", "median-wise"))
betas |
Matrix of coefficient vectors to be combined. |
method |
Method for combining vectors of coefficients. The default uses the geometric median. |
A vector of resulting coefficients.
Get coordinates on a plot by mouse-clicking.
pasteLoc(nb, digits = c(3, 3))pasteLoc(nb, digits = c(3, 3))
nb |
Number of positions. |
digits |
2 integer indicating the number of decimal places (respectively for x and y coordinates). |
A list of coordinates. Note that if you don't put the result in a variable, it returns as the command text for generating the list. This can be useful to get coordinates by mouse-clicking once, but then using the code for convenience and reproducibility.
## Not run: plot(runif(20, max = 5000)) # note the negative number for the rounding of $y coord <- pasteLoc(3, digits = c(2, -1)) text(coord, c("a", "b", "c")) ## End(Not run)## Not run: plot(runif(20, max = 5000)) # note the negative number for the rounding of $y coord <- pasteLoc(3, digits = c(2, -1)) text(coord, c("a", "b", "c")) ## End(Not run)
Partial correlation between x and y, after having adjusted both for z.
pcor(x, y, z, alpha = 0.05)pcor(x, y, z, alpha = 0.05)
x |
A numeric vector. |
y |
A numeric vector. |
z |
A data frame, which can contain characters or factors. |
alpha |
Type-I error for the confidence interval (CI).
Default is |
The partial correlation, and the lower and upper bounds of its CI.
pcor(iris[[1]], iris[[2]], iris[-(1:2)])pcor(iris[[1]], iris[[2]], iris[-(1:2)])
Plot method for class big_sp_list.
## S3 method for class 'big_sp_list' plot(x, coeff = 1, ...)## S3 method for class 'big_sp_list' plot(x, coeff = 1, ...)
x |
An object of class |
coeff |
Relative size of text. Default is |
... |
Not used. |
A ggplot2 object. You can plot it using the print method.
You can modify it as you wish by adding layers. You might want to read
this chapter
to get more familiar with the package ggplot2.
Plot method for class big_SVD.
## S3 method for class 'big_SVD' plot( x, type = c("screeplot", "scores", "loadings"), nval = length(x$d), scores = c(1, 2), loadings = 1, ncol = NULL, coeff = 1, viridis = TRUE, cols = 2, ... )## S3 method for class 'big_SVD' plot( x, type = c("screeplot", "scores", "loadings"), nval = length(x$d), scores = c(1, 2), loadings = 1, ncol = NULL, coeff = 1, viridis = TRUE, cols = 2, ... )
x |
An object of class |
type |
Either
|
nval |
Number of singular values to plot. Default plots all computed. |
scores |
Vector of indices of the two PCs to plot. Default plots the first two PCs. If providing more than two, it produces many plots. |
loadings |
Indices of PC loadings to plot. Default plots the first vector of loadings. |
ncol |
If multiple vector of loadings are to be plotted, this defines the number of columns of the resulting multiplot. |
coeff |
Relative size of text. Default is |
viridis |
Deprecated argument. |
cols |
Deprecated. Use |
... |
Not used. |
A ggplot2 object. You can plot it using the print method.
You can modify it as you wish by adding layers. You might want to read
this chapter
to get more familiar with the package ggplot2.
big_SVD, big_randomSVD and asPlotlyText.
set.seed(1) X <- big_attachExtdata() svd <- big_SVD(X, big_scale(), k = 10) # screeplots plot(svd) # 3 PCs seems "significant" plot(svd, coeff = 1.5) # larger font for papers # scores plot plot(svd, type = "scores") # first 2 PCs plot(svd, type = "scores", scores = c(1, 3)) plot(svd, type = "scores", scores = 1:4, ncol = 2, coeff = 0.7) ## add color (recall that this return a `ggplot2` object) class(obj <- plot(svd, type = "scores")) pop <- rep(c("POP1", "POP2", "POP3"), c(143, 167, 207)) library(ggplot2) print(obj2 <- obj + aes(color = pop) + labs(color = "Population")) ## change the place of the legend print(obj3 <- obj2 + theme(legend.position = c(0.82, 0.17))) ## change the title and the labels of the axes obj3 + ggtitle("Yet another title") + xlab("with an other 'x' label") # loadings plot(svd, type = "loadings", loadings = 2) ## all loadings plot(svd, type = "loadings", loadings = 1:2, coeff = 0.7, ncol = 1) # Percentage of variance explained by the PCs # See https://github.com/privefl/bigstatsr/issues/83 # dynamic plots, require the package **plotly** ## Not run: plotly::ggplotly(obj3)set.seed(1) X <- big_attachExtdata() svd <- big_SVD(X, big_scale(), k = 10) # screeplots plot(svd) # 3 PCs seems "significant" plot(svd, coeff = 1.5) # larger font for papers # scores plot plot(svd, type = "scores") # first 2 PCs plot(svd, type = "scores", scores = c(1, 3)) plot(svd, type = "scores", scores = 1:4, ncol = 2, coeff = 0.7) ## add color (recall that this return a `ggplot2` object) class(obj <- plot(svd, type = "scores")) pop <- rep(c("POP1", "POP2", "POP3"), c(143, 167, 207)) library(ggplot2) print(obj2 <- obj + aes(color = pop) + labs(color = "Population")) ## change the place of the legend print(obj3 <- obj2 + theme(legend.position = c(0.82, 0.17))) ## change the title and the labels of the axes obj3 + ggtitle("Yet another title") + xlab("with an other 'x' label") # loadings plot(svd, type = "loadings", loadings = 2) ## all loadings plot(svd, type = "loadings", loadings = 1:2, coeff = 0.7, ncol = 1) # Percentage of variance explained by the PCs # See https://github.com/privefl/bigstatsr/issues/83 # dynamic plots, require the package **plotly** ## Not run: plotly::ggplotly(obj3)
Plot method for class mhtest.
## S3 method for class 'mhtest' plot(x, type = c("hist", "Manhattan", "Q-Q", "Volcano"), coeff = 1, ...)## S3 method for class 'mhtest' plot(x, type = c("hist", "Manhattan", "Q-Q", "Volcano"), coeff = 1, ...)
x |
An object of class |
type |
Either.
|
coeff |
Relative size of text. Default is |
... |
Not used. |
A ggplot2 object. You can plot it using the print method.
You can modify it as you wish by adding layers. You might want to read
this chapter
to get more familiar with the package ggplot2.
big_univLinReg, big_univLogReg, plot.big_SVD and asPlotlyText.
set.seed(1) X <- big_attachExtdata() y <- rnorm(nrow(X)) test <- big_univLinReg(X, y) plot(test) plot(test, type = "Volcano") plot(test, type = "Q-Q") plot(test, type = "Manhattan") plot(test, type = "Manhattan") + ggplot2::ggtitle(NULL)set.seed(1) X <- big_attachExtdata() y <- rnorm(nrow(X)) test <- big_univLinReg(X, y) plot(test) plot(test, type = "Volcano") plot(test, type = "Q-Q") plot(test, type = "Manhattan") plot(test, type = "Manhattan") + ggplot2::ggtitle(NULL)
Predict method for class big_sp.
## S3 method for class 'big_sp' predict(object, X, ind.row, ind.col, covar.row = NULL, ncores = 1, ...)## S3 method for class 'big_sp' predict(object, X, ind.row, ind.col, covar.row = NULL, ncores = 1, ...)
object |
Object of class |
X |
An object of class FBM. |
ind.row |
An optional vector of the row indices that are used. If not specified, all rows are used. Don't use negative indices. |
ind.col |
An optional vector of the column indices that are used. If not specified, all columns are used. Don't use negative indices. |
covar.row |
Matrix of covariables to be added in each model to correct
for confounders (e.g. the scores of PCA), corresponding to |
ncores |
Number of cores used. Default doesn't use parallelism. You may use nb_cores. |
... |
Not used. |
A vector of scores, corresponding to ind.row.
big_spLinReg and big_spLogReg.
Predict method for class big_sp_list.
## S3 method for class 'big_sp_list' predict( object, X, ind.row = rows_along(X), ind.col = attr(object, "ind.col"), covar.row = NULL, proba = (attr(object, "family") == "binomial"), base.row = NULL, ncores = 1, ... )## S3 method for class 'big_sp_list' predict( object, X, ind.row = rows_along(X), ind.col = attr(object, "ind.col"), covar.row = NULL, proba = (attr(object, "family") == "binomial"), base.row = NULL, ncores = 1, ... )
object |
Object of class |
X |
An object of class FBM. |
ind.row |
An optional vector of the row indices that are used. If not specified, all rows are used. Don't use negative indices. |
ind.col |
An optional vector of the column indices that are used. If not specified, all columns are used. Don't use negative indices. |
covar.row |
Matrix of covariables to be added in each model to correct
for confounders (e.g. the scores of PCA), corresponding to |
proba |
Whether to return probabilities? |
base.row |
Vector of base predictions, corresponding to |
ncores |
Number of cores used. Default doesn't use parallelism. You may use nb_cores. |
... |
Not used. |
A vector of scores, corresponding to ind.row.
big_spLinReg and big_spLogReg.
Get the scores of PCA associated with an svd decomposition (class big_SVD).
## S3 method for class 'big_SVD' predict( object, X = NULL, ind.row = rows_along(X), ind.col = cols_along(X), block.size = block_size(nrow(X)), ... )## S3 method for class 'big_SVD' predict( object, X = NULL, ind.row = rows_along(X), ind.col = cols_along(X), block.size = block_size(nrow(X)), ... )
object |
A list returned by |
X |
An object of class FBM. |
ind.row |
An optional vector of the row indices that are used. If not specified, all rows are used. Don't use negative indices. |
ind.col |
An optional vector of the column indices that are used. If not specified, all columns are used. Don't use negative indices. |
block.size |
Maximum number of columns read at once. Default uses block_size. |
... |
Not used. |
A matrix of size where n is the number of samples
corresponding to indices in ind.row and K the number of PCs
computed in object. If X is not specified, this just returns
the scores of the training set of object.
set.seed(1) X <- big_attachExtdata() n <- nrow(X) # Using only half of the data ind <- sort(sample(n, n/2)) test <- big_SVD(X, fun.scaling = big_scale(), ind.row = ind) str(test) plot(test$u) pca <- prcomp(X[ind, ], center = TRUE, scale. = TRUE) # same scaling all.equal(test$center, pca$center) all.equal(test$scale, pca$scale) # scores and loadings are the same or opposite # except for last eigenvalue which is equal to 0 # due to centering of columns scores <- test$u %*% diag(test$d) class(test) scores2 <- predict(test) # use this function to predict scores all.equal(scores, scores2) dim(scores) dim(pca$x) tail(pca$sdev) plot(scores2, pca$x[, 1:ncol(scores2)]) plot(test$v[1:100, ], pca$rotation[1:100, 1:ncol(scores2)]) # projecting on new data X2 <- sweep(sweep(X[-ind, ], 2, test$center, '-'), 2, test$scale, '/') scores.test <- X2 %*% test$v ind2 <- setdiff(rows_along(X), ind) scores.test2 <- predict(test, X, ind.row = ind2) # use this all.equal(scores.test, scores.test2) scores.test3 <- predict(pca, X[-ind, ]) plot(scores.test2, scores.test3[, 1:ncol(scores.test2)])set.seed(1) X <- big_attachExtdata() n <- nrow(X) # Using only half of the data ind <- sort(sample(n, n/2)) test <- big_SVD(X, fun.scaling = big_scale(), ind.row = ind) str(test) plot(test$u) pca <- prcomp(X[ind, ], center = TRUE, scale. = TRUE) # same scaling all.equal(test$center, pca$center) all.equal(test$scale, pca$scale) # scores and loadings are the same or opposite # except for last eigenvalue which is equal to 0 # due to centering of columns scores <- test$u %*% diag(test$d) class(test) scores2 <- predict(test) # use this function to predict scores all.equal(scores, scores2) dim(scores) dim(pca$x) tail(pca$sdev) plot(scores2, pca$x[, 1:ncol(scores2)]) plot(test$v[1:100, ], pca$rotation[1:100, 1:ncol(scores2)]) # projecting on new data X2 <- sweep(sweep(X[-ind, ], 2, test$center, '-'), 2, test$scale, '/') scores.test <- X2 %*% test$v ind2 <- setdiff(rows_along(X), ind) scores.test2 <- predict(test, X, ind.row = ind2) # use this all.equal(scores.test, scores.test2) scores.test3 <- predict(pca, X[-ind, ]) plot(scores.test2, scores.test3[, 1:ncol(scores.test2)])
Predict method for class mhtest.
## S3 method for class 'mhtest' predict(object, scores = object$score, log10 = TRUE, ...)## S3 method for class 'mhtest' predict(object, scores = object$score, log10 = TRUE, ...)
object |
An object of class |
scores |
Raw scores (before transformation) that you want to transform to p-values. |
log10 |
Are p-values returned on the |
... |
Not used. |
Vector of log10(p-values) associated with scores and object.
big_univLinReg and big_univLogReg.
Replace extension '.bk'
sub_bk(path, replacement = "", stop_if_not_ext = TRUE)sub_bk(path, replacement = "", stop_if_not_ext = TRUE)
path |
String with extension '.bk'. |
replacement |
Replacement of '.bk'. Default replaces by nothing. |
stop_if_not_ext |
If |
String with extension '.bk' replaced by replacement.
path <- "toto.bk" sub_bk(path) sub_bk(path, ".rds")path <- "toto.bk" sub_bk(path) sub_bk(path, ".rds")
Summary method for class big_sp_list.
## S3 method for class 'big_sp_list' summary(object, best.only = FALSE, sort = FALSE, ...)## S3 method for class 'big_sp_list' summary(object, best.only = FALSE, sort = FALSE, ...)
object |
An object of class |
best.only |
Whether to return only one row corresponding to the best
model? The best model is the one smallest |
sort |
Whether to sort by |
... |
Not used. |
A tibble with, for each $alpha, a mean $validation_loss, a mean
vector of coefficients $beta, the corresponding number of non-zero
coefficients $nb_var, and the reasons of method completion $message.
Theme ggplot2 used by this package.
theme_bigstatsr(size.rel = 1)theme_bigstatsr(size.rel = 1)
size.rel |
Relative size. Default is |
library(ggplot2) (p <- ggplot(mapping = aes(x = 1:10, y = 1:10)) + geom_point()) p + theme_bw() p + theme_bigstatsr()library(ggplot2) (p <- ggplot(mapping = aes(x = 1:10, y = 1:10)) + geom_point()) p + theme_bw() p + theme_bigstatsr()
Temporarily disable downcast warning
without_downcast_warning(expr)without_downcast_warning(expr)
expr |
The expression to evaluate without downcast warning. |
The result of the evaluated expression.
without_downcast_warning(FBM(10, 10, type = "integer", init = 1.5))without_downcast_warning(FBM(10, 10, type = "integer", init = 1.5))