Adding comment in C++ code for debugging purpose
?s 13:38 de 17/12/2022, Christofer Bogaso escreveu:
Hi,
Below is the position of Rcout and underlying C++ function
#ifdef _OPENMP
#include <omp.h>
#endif
// [[Rcpp::depends(RcppProgress)]]
#include <progress.hpp>
#include "cpploss.h"
#include <Rcpp.h>
#include <Rmath.h>
#include <iostream>
using namespace Rcpp;
// [[Rcpp::export]]
SEXP GCPM_cpploss(SEXP default_distr_a,SEXP link_function_a, SEXP
S_a,SEXP Sigma_a, SEXP W_a, SEXP PD_a, SEXP PL_a, SEXP calc_rc_a, SEXP
loss_thr_a, SEXP max_entries_a){
Rcpp::Rcout << "Some Value" << std::endl << 1.23 << std::endl;
NumericMatrix S(S_a), W(W_a),Sigma(Sigma_a);
NumericVector PD(PD_a),
PL(PL_a),max_entries(max_entries_a),default_distr(default_distr_a),link_function(link_function_a),calc_rc(calc_rc_a),loss_thr(loss_thr_a);
List ret;
etc
This still does not print in the console.
Not sure if I am missing something.
Thanks and regards,
On Sat, Dec 17, 2022 at 6:57 PM Rui Barradas <ruipbarradas at sapo.pt> wrote:
?s 11:05 de 17/12/2022, Christofer Bogaso escreveu:
Hi Rui,
Unfortunately, the code Rcpp::Rcout << "---------->>>>>.My values" <<
"\n"; still not printing the value.
Regarding your second suggestion, R_Print("My values\n"); - where
should I put this statement?
On Sat, Dec 17, 2022 at 11:39 AM Rui Barradas <ruipbarradas at sapo.pt> wrote:
?s 23:32 de 16/12/2022, Christofer Bogaso escreveu:
Hi, I am using an R package where there are some C++ code. To check some intermediate values generated by that C++ code, I added a line like std::cout << "My values"; Now with this modification, I next build a modified package (source) using R CMD build Next I install this modified package using install.packages() function However during the run-time of the C++ code with above modification, I dont get any print with "My values" Can you please help to understand why am not getting that printed?
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Hello,
If the package uses Rcpp try instead
Rcpp::Rcout << "My values" << "\n"; // or std::endl
More generally, there is also
R_Print("My values\n");
Hope this helps,
Rui Barradas
Hello, Put R_Print where your cout is and instead of it. As for Rcpp::Rcout, instead of "\n" try ending the line with std::endl to immediately flush the buffer. Hope this helps, Rui Barradas
Hello,
1. Forget R_print, it is meant for C code, not for Rcpp.
Besides, it is also an error of mine, I was thinking about Rprintf,
see below.
2. The following works as expected.
It's the first example in
vignette("Rcpp-introduction", package = "Rcpp")
with the if/Rcout and Rprintf instructions added.
File: convolve_rcpp.cpp
#include "Rcpp.h"
using namespace Rcpp;
// [[Rcpp::export]]
NumericVector convolve_cpp(const NumericVector& a, const NumericVector& b) {
// Declare loop counters, and vector sizes
int i, j,
na = a.size(), nb = b.size(),
nab = na + nb - 1;
// Create vector filled with 0
NumericVector ab(nab);
// Crux of the algorithm
for(i = 0; i < na; i++) {
// this works as expected, it prints to the console
// printing is on every 10 times through the loop
if(i % 10 == 0) {
Rcpp::Rcout << "Some Value " << i << "\n";
Rcpp::Rcout << " Value " << a[i] << std::endl;
}
for(j = 0; j < nb; j++) {
ab[i + j] += a[i] * b[j];
}
}
Rprintf("Done\n");
// Return result
return ab;
}
Then run the R script
path <- "~/path/to/Rcpp/code"
fl <- list.files(path, pattern = "convolve\\.cpp")
fl <- file.path(path, fl)
Rcpp::sourceCpp(fl)
x <- 1:1e4
y <- 10:1
z <- convolve_cpp(x, y)
str(z)
# num [1:10009] 10 29 56 90 130 175 224 276 330 385 ...
Hope this helps,
Rui Barradas