gRbase (version 1.8-5.1)

gRbase_utilities: gRbase utilities

Description

Various utility functions for gRbase. Includes 'faster versions' of certain standard R functions.

Usage

rhsFormula2list(form)
rhsf2list(form)
list2rhsFormula(form)
list2rhsf(form)
rowmat2list(X)
colmat2list(X)
matrix2list(X, byrow = TRUE)
which.arr.index(X)
which_matrix_index(X)
rowSumsPrim(X)
colSumsPrim(X)
colwiseProd(v, X)

Arguments

form

Formula specification (a right-hand sided formula, a numeric/character vector or a list of vectors).

X

A matrix.

byrow

Should the split be by row or by column.

v

A vector.

Details

which.arr.ind: Returns matrix n x 2 matrix with indices of non-zero entries in matrix X. Notice which_matrix_index__ is cpp implementation.

colwiseProd: multiplies a vector v and a matrix X columnwise (as opposed to rowwise which is achieved by v * X). Hence colwiseProd does the same as t(v * t(X)) - but it does so faster for numeric values.

Examples

# NOT RUN {
## colwiseProd
X <- matrix(1:16, nrow=4)
v <- 1:4
t(v * t(X))
colwiseProd(v, X)
# }
# NOT RUN {
system.time(for (ii in 1:100000)  t(v * t(X)))
system.time(for (ii in 1:100000)  colwiseProd(v, X))
# }
# NOT RUN {
# }