Displaying 20 results from an estimated 1200 matches similar to: "simple C function segfaults"
2006 Mar 07
2
double pointer matrix
Hello,
I'm having some difficulty to understand how I could
take the proper result from the following listing:
-- cut ---
#include <stdlib.h>
#include <R.h>
#include <Rmath.h>
void retMat ( double **y, int *n, int *m, double *a,
double *b) {
int i, j;
y = malloc( (*n) * sizeof( double ) );
for (i=0; i<*n; i++) {
y[i] = malloc (
2004 Mar 03
1
generating normal numbers: GetRNGstate, PutRNGstate
Hi
I'd like to generate thousands of normal numbers from my C function using
the C API functions provided R. I have two options:
1. double norm_rand(); (page 61 of R extension 1.8.1)
2. double rnorm(double mu, double sigma); (page 58 of R extension 1.8.1)
If my understanding of R-exts is correct, then I only need to call
GetRNGstate once, and then call 1000 norm_rand, and then call
2008 Jul 03
1
GetRNGstate and PutRNGstate
Hi,
I've got a simulation function, written in C and called from R, that
uses the R random number functions. It's not a very complicated
simulation - 280 lines total, with the main function (the one called
with .C) repeatedly calling another function, with multiple calls to
unif_rand() in both functions. At the beginning of the main function I
call GetRNGstate(), and the last thing I do
2005 Jun 28
1
GetRNGstate() crashes in Windows
Hi,
Has anyone managed to successfully call GetRNGstate() / PutRNGstate()
without crashing in a Windows environment (spec. XP)? I've compiled
successfully using both the latest Cygwin, latest Mingw, and the version
of Mingw suggested in "Building R for Windows" website, but when the
executable runs, it crashes; the functions themselves can run when I omit
2006 Jan 05
2
random seed question
Greetings,
I am trying to write a C++ subroutine of my random number generator. Based
on tutorial in Writing R Extensions, one should call GetRNGstate() before
and PutRNGstate() after calling R's random variate generation routines. Now
suppose my function would generate n(n>1) numbers by a loop, do I need to
call these two functions at each iteration? This certainly increases
computation
2002 Jan 24
2
random number generation issues with r and compiled C code
Dear People,
I have been writing a simulation routine that is currently entirely
written in c++. I've been using the R standalone math library to give me
random number generation for this. However, I have had to set the seed
myself, and I am using
set_seed(time(NULL), clock)
for every call to unif_rand().
However, this works really badly. The random numbers aren't uniform at
all. Does
2009 Nov 13
2
random numbers in C
I need some random numbers in my C program. Here a small example:
////////////////////////////////////////////////////////////////////////////////
#include <R.h>
void rand (int* n)
{
int len = *n;
for (int i = 0; i < len; i++)
Rprintf("%1.5f ", unif_rand());
}
dyn.load("rand.dll")
.C("rand", as.integer(10))
dyn.unload("rand.dll")
2005 Jun 14
3
Calling C from Fortran
I would like to call C routines from Fortran under linux as suggested in
section 5.6 of
the "Writing R extensions" documentation.
I'm familiar with Fortran but not with C.
I understand the example provided in Fortran:
subroutine testit()
double precision normrnd, x
call rndstart()
x = normrnd()
call dblepr("X was", 5, x, 1)
call rndend()
end
but I don't understand
2005 Jun 14
1
Calling C from Fortran
I would like to call C routines from Fortran as suggested in section 5.6 of
the "Writing R extensions" documentation.
I'm familiar with Fortran but not with C.
I understand the example provided in Fortran:
subroutine testit()
double precision normrnd, x
call rndstart()
x = normrnd()
call dblepr("X was", 5, x, 1)
call rndend()
end
but I don't understand the purpose
2002 Jan 14
1
trouble using R Mathlib as standalone
Dear People,
I am trying to use R's Math library as standalone, as documented in
/src/nmath/standalone. I am using C++ in Debian testing, and the versions
are as follows:
ii g++-3.0 3.0.3-1 The GNU C++ compiler.
ii r-mathlib 1.4.0-1 `GNU S' - Standalone R math library
I have a file (rand.cc) as follows. I don't think that lattice.hh or mh.hh
are very
2010 Jun 15
1
Error when callin g C-Code
Hi
when I call the function below in R, i get the error: Object 'pairlist'
can't be converted to 'double'.
#include <R.h>
#include <Rdefines.h>
#include <Rmath.h>
SEXP CSimPoisson(SEXP lambda, SEXP tgrid, SEXP T2M, SEXP Ni, SEXP NT)
{
double sign, EVar;
double *xlambda, *xtgrid, *xT2M, *xNi, *xNT, *xtau;
SEXP tau;
int ltgrid =0;
int i = 0;
int j = 0;
2012 Sep 07
7
Producing a table with mean values
Hi All,
I have a data set wit three size classes (pico, nano and micro) and 12
different sites (Seamounts). I want to produce a table with the mean and
standard deviation values for each site.
Seamount Pico Nano Micro Total_Ch
1 Off_Mount 1 0.0691 0.24200 0.00100 0.31210
2 Off_Mount 1 0.0938 0.00521 0.02060 0.11961
3 Off_Mount 1 0.1130 0.20000 0.06620 0.37920
4 Off_Mount 1
2005 Nov 30
1
RNG stuck via Fortran call
Having not much success with my previous question I try to reformulate it:
I'm simulating a Markow chain in Fortran interfaced with R.
Each loop of my Fortran calls various functions of the R RNG through
the wrapper given below.
In a run of 100 iterations of the Markov kernel,
after 20 iterations, the RNG seems like frozen.
For example, the first call to the RNG in my loop is:
2011 Nov 17
3
.Call in R
Hi R developers,
I am new to this forum and hope someone can help me with .Call in R.
Greatly appreciate any help!
Say, I have a vector called "vecA" of length 10000, I generate a vector
called "vecR" with elements randomly generated from Uniform[0,1]. Both vecA
and vecR are of double type. I want to replace elements vecA by elements in
vecR only if sum of elements in
2012 Sep 11
4
Maintaining specific order when using aggregate or change order on axis
Hi All,
I'm using the following code to produce some stacked bar graphs.
*setwd("C:\\Users\\Tinus\\Documents\\NMMU\\R\\Seamounts")*
*SChla <- read.csv("SM_Chla_data.csv")*
*
*
*#Extract mean values from data file*
*
*
*Coral <- SChla[185:223,] #Reduce SChla to Coral only*
*coral <- with(Coral , aggregate(cbind(Pico, Nano, Micro),
list(Depth),FUN=mean))*
2009 Jun 30
3
Matrix with random number
Hello!
I have a program in Fortran and would like to build a matrix with random numbers, I have a function in C.
However, I have problems with the use of function in R.
Code to compile: R CMD SHLIB mat.f myrbeta.c -o func.so
Code in C.
#include <R.h>
#include <Rmath.h>
void F77_SUB(fseedi)(void){
GetRNGstate();
}
void F77_SUB(fseedo)(void){
PutRNGstate();
}
void
2006 Aug 03
1
question about dll crashing R
I have ported some R code to C to make it faster.
I can perform .Call("foobar",....) once and it
works fine. Absolutely correct answer.
If I put a loop inside foobar and run the main code
routine more than 100 times, it crashes R.
Or if I call .Call("foobar"....) seperately more than
two tims it crashes R.
For the most part I am doing matirx multiplies using
EXP
1998 Nov 03
2
smbclient sees the virtual samba server but not the windows clients
Hello Again!
I now have a virtual host serving (almost) samba and a real one serving
samba under the original name.
On the local machine, I can access the the virtual host through smbclient
and smbmount. Everything seems all right. Unfortunately, the virtual host
won't serve the windows-9x machines. The virtual (and real) host both
appear on the network browse list but when the win clients
2012 Sep 19
2
Help reproducing a contour plot
Hi All,
I am trying to reproduce this using R instead.
[image: Full-size image (38 K)]
I tried using the following code
*SChla <- read.csv("SM_Chla_data.csv")*
*Atlantis <- SChla[16:66,]*
*head(Atlantis)*
*
*
Seamount Station Depth Pico Nano Micro Total_Ch dbar Latitude
Longitud
16 Atlantis 1217 Surface 0.0639 0.1560 0.0398 0.2597 2.082 -32.71450
57.29733
2009 Jul 30
3
user supplied random number generators
?Random.user says (in svn trunk)
Optionally,
functions \code{user_unif_nseed} and \code{user_unif_seedloc} can be
supplied which are called with no arguments and should return pointers
to the number of seeds and to an integer array of seeds. Calls to
\code{GetRNGstate} and \code{PutRNGstate} will then copy this array to
and from \code{.Random.seed}.
And it offers as an example
void