sparseMatrix-utils {DelayedArray} | R Documentation |
sparseMatrix utilities
Description
Some utilities to operate natively on sparseMatrix objects (e.g. dgCMatrix and lgCMatrix objects) from the Matrix package. Mostly for internal use by the DelayedArray package.
Usage
## rowsum() and colsum() S4 generics:
#rowsum(x, group, reorder=TRUE, ...)
#colsum(x, group, reorder=TRUE, ...)
## Default methods:
## S4 method for signature 'ANY'
rowsum(x, group, reorder=TRUE, ...)
## S4 method for signature 'ANY'
colsum(x, group, reorder=TRUE, ...)
## rowsum() method for dgCMatrix objects:
## S4 method for signature 'dgCMatrix'
rowsum(x, group, reorder=TRUE, ...)
Arguments
x |
A numeric matrix-like object. |
group , reorder , ... |
See |
Value
See ?base::rowsum
for the value returned
by the default rowsum
method.
The default colsum
method returns
t(rowsum(t(x), group, reorder=reorder, ...))
.
See Also
-
DelayedMatrix-utils in this package for the
rowsum
andcolsum
methods defined for DelayedMatrix objects. -
base::rowsum
in the base package for the defaultrowsum
method. -
dgCMatrix objects in the Matrix package.
Examples
m0 <- rsparsematrix(1e5, 800, density=0.15) # sparse representation
m <- as.matrix(m0) # dense representation
group <- sample(20, nrow(m), replace=TRUE)
## 'rowsum(m0)' is about 4x faster than 'rowsum(m)':
rs0 <- rowsum(m0, group)
rs <- rowsum(m, group)
stopifnot(identical(rs0, rs))
[Package DelayedArray version 0.22.0 Index]