benchmarking armamax against apply and pmax

benchmark.r

library(inline)
library(Rcpp)

cpp <- 'arma::mat A  = Rcpp::as<arma::mat>(X_);
  arma::vec y(A.n_rows);
	arma::rowvec tmp(A.n_cols);
  for (int i=0; i<A.n_rows; i++) {
    tmp = A.row(i);
    y(i) = tmp.max();
  }
return wrap(y);
'

cat('rows >> columns')
armaf <- cxxfunction(signature(X_="matrix"),body=cpp,plugin="RcppArmadillo")
A = matrix(rnorm(400000),2000,50)
Ad = as.data.frame(A)
all.equal(do.call(pmax,as.data.frame(A)),as.numeric(armaf(A)))
benchmark(R.do.call=do.call(pmax,Ad),armamax=armaf(A),replications=100)
benchmark(R.apply=apply(A,1,max),armamax=armaf(A),replications=100)

cat('columns >> rows')
A = matrix(rnorm(400000),50,2000)
Ad = as.data.frame(A)
all.equal(do.call(pmax,as.data.frame(A)),as.numeric(armaf(A)))
benchmark(R.do.call=do.call(pmax,Ad),armamax=armaf(A),replications=100)
benchmark(R.apply=apply(A,1,max),armamax=armaf(A),replications=100)