colSumsCrossprod: Apply crossprod and colSums

In riskRegression: Risk Regression Models and Prediction Scores for Survival Analysis with Competing Risks

Description

Fast computation of crossprod(colSums(X),Y)

Usage

colSumsCrossprod(X, Y, transposeY)

Arguments

X	A matrix with dimensions k*n. Hence the result of colSums(X) has length n.
Y	A matrix with dimenions n*m. Can be a matrix with dimension m*n but then transposeY should be TRUE.
transposeY	Logical. If TRUE transpose Y before matrix multiplication.

Value

A vector of length m.

Author(s)

Thomas Alexander Gerds <[e-mail]>

Examples

x <- matrix(1:8,ncol=2)
y <- matrix(1:16,ncol=8)
colSumsCrossprod(x,y,0)

x <- matrix(1:8,ncol=2)
y <- matrix(1:16,ncol=2)
colSumsCrossprod(x,y,1)

riskRegression documentation built on Jan. 13, 2021, 11:12 a.m.