romainfrancois

library("devtools")
library("testthat")

install_github( "Rcpp11/Rcpp11")
install_github( "Rcpp11/Rcpp-test")

library( "RcppTest" )

test_package( "RcppTest" )

romainfrancois

Trying to sourceCpp the test.cpp, I get all that on windows with gcc 4.6.3

romainfrancois

Several implementations of the problem from this SO thread. http://stackoverflow.com/questions/22886040/how-should-i-count-the-number-of-unique-rows-in-a-binary-matrix

The counts_cpp2.cpp is similar to the one I detailed in my SO answer. The counts_cpp3.cpp goes further by splitting the job into 4 threads, each dealing with a subset of rows of the matrix.

The graph shows the times of both solutions.

• The first line on the bottom corresponds to the sequential version. Red is hashing and blue is training the hash map
• The other 4 lines above are the times of the 4 threads of the parallel solution. Black is when the main threads joins the orker threads, and orange is merging the hash maps.

romainfrancois

$ R CMD SHLIB try_catch.c
clang -I/Library/Frameworks/R.framework/Resources/include -DNDEBUG  -I/usr/local/include    -fPIC  -g -O3 -Wall -pipe -c try_catch.c -o try_catch.o
clang -dynamiclib -Wl,-headerpad_max_install_names -undefined dynamic_lookup -single_module -multiply_defined suppress -L/usr/local/lib -L/usr/local/lib -o try_catch.so try_catch.o -F/Library/Frameworks/R.framework/.. -framework R -Wl,-framework -Wl,CoreFoundation

When throwing a real condition, e.g. a simpleError, I can get hold of it

romain@naxos /tmp $ Rscript -e "dyn.load('try_catch.so') ; .Call( 'test', 1L)"

romainfrancois

ccall <- function(fun, ..., depends = character(), plugins = character(), verbose = FALSE ){ 
  dots <- list(...)    
  if( length(dots) ){
    code <- sprintf( '
    SEXP fun(%s){
      return wrap( %s( %s ) ) ;
    }',
    paste( sprintf( "SEXP arg%d", seq_along(dots)), collapse = ", " ),
    fun, 
    paste( sprintf( "Rcpp::internal::converter(arg%d)", seq_along(dots) ), collapse = ", " )

romainfrancois

library("httr")
library("rjson")

internal <- function(fun){
  names.c <- content( GET("https://raw2.github.com/wch/r-source/trunk/src/main/names.c") )
  names.c <- strsplit( names.c, "\\n" )[[1L]]
  
  rx <- sprintf('^[{]"%s"', fun )
  match <- grep( rx, names.c)
  if( length(match) != 1L ){

romainfrancois

> bench(1000)
Unit: microseconds
                     expr    min      lq   median       uq     max neval
                 which(b)  2.104   4.548   5.1000   6.0955  18.306   100
 which_cpp_nthreads(b, 2) 26.401  28.303  28.9285  30.0625 103.980   100
 which_cpp_nthreads(b, 4) 45.902  49.494  50.6335  52.1155 115.184   100
 which_cpp_nthreads(b, 8) 97.596 100.143 101.3720 104.9895 270.521   100

> bench(1e+05)
Unit: microseconds

romainfrancois

ndiff <- 2597797
  f <- function(){
    n <- round(runif( 1, min = 4, max = 10 ))
    paste( sample(letters, n, replace = TRUE ), collapse = "" )
  }
  a <- replicate( ndiff, f() )
  b <- replicate( ndiff, f() )
  
  rows <- sample( 1:ndiff, 3018671, replace = T )
  cols <- sample( c(T,F), 3018671, replace = T )

romainfrancois

#include <Rcpp.h>
#include <thread>
#include <future>

using namespace Rcpp ;

typedef NumericVector::iterator Iterator ;
  
struct count_positive {
  int operator()(Iterator first, Iterator last){

romainfrancois

library(Rcpp)
library(microbenchmark)

vectorized <- function() {
  a <- c(1, 1)
  b <- c(2, 2)
  
  for (i in 1:1000000) {
    x <- a + b
  }