#!/usr/bin/Rscript
set.seed (1)
m <- 10000
n <-  5000
A <- matrix (runif (m*n),m,n)
cat("Matrix Multiply\n")
invisible(gc())
system.time (B <- crossprod(A))
cat("Cholesky Factorization\n")
invisible(gc())
system.time (C <- chol(B))
rm(B,C)
m <- 10000
n <- 2000
A <- matrix (runif (m*n),m,n)
cat("Singular Value Decomposition\n")
invisible(gc())
system.time (S <- svd (A,nu=0,nv=0))
rm(S)
m <- 10000
n <- 2000
A <- matrix (runif (m*n),m,n)
cat("Principal Components Analysis\n")
invisible(gc())
system.time (P <- prcomp(A))
rm(P)
require ('MASS')
g <- 5
k <- round (m/2)
A <- data.frame (A, fac=sample (LETTERS[1:g],m,replace=TRUE))
train <- sample(1:m, k)
cat("Linear Discriminant Analysis\n")
invisible(gc())
system.time (L <- lda(fac ~., data=A, prior=rep(1,g)/g, subset=train)) 
q("no")