fntl (version 0.1.1)

matrix_apply: Matrix Apply Functions

Description

Matrix Apply Functions

Usage

mat_apply(X, f)
row_apply(X, f)
col_apply(X, f)

Value

mat_apply returns a matrix. row_apply and col_apply return a vector. See section "Apply" of the package vignette for details.

Arguments

X

A matrix

f

The function to apply.

Details

The mat_apply, row_apply, and col_apply C++ functions are intended to operate like the following calls in R, respectively.

apply(x, c(1,2), f)
apply(x, 1, f)
apply(x, 2, f)

The R functions exposed here are specific to numeric-valued matrices, but the underlying C++ functions are intended to work with any type of Rcpp Matrix.

Examples

X = matrix(1:12, nrow = 4, ncol = 3)
mat_apply(X, f = function(x) { x^(1/3) })
row_apply(X, f = function(x) { sum(x^2) })
col_apply(X, f = function(x) { sum(x^2) })