[Rcpp-devel] Vector allocation memory problem

Hmmm. I think you just need "i<n" instead of "i<=n" in your for construct.

Romain



Le 8 avr. 2011 ? 10:12 AM, Cedric Ginestet 
<c.ginestet05 at googlemail.com <mailto:c.ginestet05 at googlemail.com>> a 
?crit :

Hi guys,

I have encountered a reproducible error in using Rcpp, which I have 
reported below. Basically, while allocation of elements in a vector 
to a particular value works well for vectors of small sizes, this 
returns an error when the size of that vector is increased. Either it 
returns a giblc error or it hangs and never resumes. I have 
reproduced this error on two different Linux distributions (Ubuntu 
10.10 and 10.04 with g++ 4.4.1 and R 2.12.1).

####################################################
library(Rcpp)
library(inline)

src <- '
  Rcpp::IntegerMatrix xA(A);
  int n=xA.nrow();
  NumericVector dist(n);
  for(int i=0;i<=n;i++){dist[i]=1.0;}
  return dist;'
cxxfun <- 
cxxfunction(sig=signature(A="matrix"),body=src,plugin="Rcpp",verbose=TRUE)

## Tests.
n <- 20; A <- matrix(0,n,n); dist <- cxxfun(A);
n <- 200; A <- matrix(0,n,n); dist <- cxxfun(A);
n <- 2000; A <- matrix(0,n,n); dist <- cxxfun(A);
*** glibc detected *** /usr/lib/R/bin/exec/R: double free or 
corruption (!prev): 0x08cfc278 ***

####################################################

Is there something that I doing wrong there?
Thank you very much for your help,
Ced


-- 
Cedric Ginestet
Centre for Neuroimaging Sciences (L3.04)
NIHR Biomedical Research Centre
Institute of Psychiatry, Box P089
Kings College London
De Crespigny Park
London
SE5 8AF