Displaying 20 results from an estimated 6000 matches similar to: "random numbers in C"
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
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
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
2009 Nov 16
2
(Parallel) Random number seed question...
Hi All,
I have k identical parallel pieces of code running, each using n.rand
random numbers.? I would like to use the same RNG (for now), and set
the seeds so that I can guarantee that there are no overlaps in the
random numbers sampled by the k pieces of code.? Another side goal is
to have reproducibility of my results.? In?the past I have used C with
SPRNG for this task, but I'm hoping
2006 Jun 08
1
Problems Building R-2.3.1 on Alpha server ES40 running Tru64 V5.1B PK#5
R Listers,
One of the list contributors suggested I abandon attempts to build
R-1.9.1 and focus on building R-2.3.1. I believe the main set of
packages have been built properly (with some changes to the code) -
however, when building the Recommended packages, the build fails.
CODE CHANGES:
=============
1. My C compiler requires a ";" on line 589 of
..../src/main/printutils.c. Here
2008 Aug 06
1
error in installing R packages
Hello,
I am trying to install R packages under linux, some of the packages can
not be installed and I got the following error, could anybody give me
suggestion on where the problem is and how to fix it? Thanks-e
> .libPaths()
[1] "/usr/lib64/R/library"
[2] "/usr/share/R/library"
[3]
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
2015 Apr 21
2
shlib problems with Intel compiler
Hi,
I'm encountering trouble compiling caTools_1.17.1.tar.gz and e1071_1.6-4.tar.gz on a Linux system using the Intel compiler suite. 14 other packages I generally use installed without any trouble. I notice both of these trouble packages have a C++ component, so I wonder if that might be the issue. Below, there's information on my platform, compiler, and some diagnostic output showing
2010 Jan 28
1
Problem with R math library.
Hello.
I've been working on my OCaml-R binding, and I quite pleased to see that
it is functional, though far from being perfect or polished. You can
find the gitweb webpage and the interface documentation at
http://yziquel.homelinux.org/gitweb/?p=ocaml-r.git;a=tree
http://yziquel.homelinux.org/topos/api/ocaml-r/index.html
I'm having unexpected trouble with the math library, though.
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
2004 Mar 23
1
R equivilant to RAND_MAX in C
Hello,
I have some C code that I'm interfacing to R using the .C calling
interface. Currently the C code uses the rand() function from the GNU C
library to generate random numbers. Since I need the random numbers in a
range from 0 to a (where a is an integer) I use the RAND_MAX macro as
(int)(rand() * (float)(*nobs-1) / (RAND_MAX+1.0))
(taken from the rand() manpage)
However, since I have
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
2007 Jun 06
3
C function with unknown output length
Hi all,
Could anyone point me to one or more examples in the R sources of a C
function that is called without knowing in advance what will be the
length (say) of the output vector?
To make myself clearer, we have a C function that computes
probabilities until their sum gets "close enough" to 1. Hence, the
number of probabilities is not known in advance.
I would like to have an
2006 Jun 29
1
using "rbinom" in C code gives me erroneous results... random variable is not random (always zero)...
Dear Listers,
I am trying to use "rbinom" in my C code, but i always get zeros as output no matter the probability. Am not sure what I am doing wrong because the function has worked before. Attached in an example. Noticed that "rbinom" expects 'n' to be REAL.
Regards, Vumani
R 2.3.1 (2006-06-01)
Windows XP
Gcc
/* Called this file binom.c and then ran rcmd shlib on it
2015 Apr 22
1
shlib problems with Intel compiler
Hi Martyn,
Thanks for your insight, that seems pretty direct. Unfortunately, I did not compile this version of R (it's on a large supercomputer system and this version of R was installed by the admins). Using "R CMD config", I see the following relevant settings:
DYLIB_LD = icc -std=gnu99
DYLIB_LDFLAGS = -shared -openmp
LDFLAGS = -L/opt/compilers/intel/cce/9.1.039/lib
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
2018 Sep 20
4
Bias in R's random integers?
Hello,
On Thursday, September 20, 2018 11:15:04 AM EDT Duncan Murdoch wrote:
> On 20/09/2018 6:59 AM, Ralf Stubner wrote:
> > On 9/20/18 1:43 AM, Carl Boettiger wrote:
> >> For a well-tested C algorithm, based on my reading of Lemire, the
> >> unbiased "algorithm 3" in https://arxiv.org/abs/1805.10941 is part
> >> already of the C standard library in
2006 Feb 21
4
simple C function segfaults
Hello,
I use the simplest of examples that somebody can think
of in order to generate a matrix of random numbers
from within C, calling appropriate R functions. The
concrete example is below:
--- file pico.c
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <R.h>
#include <Rmath.h>
#define COLM( i, j, m ) ( m*j + i)
void pico ( double *y, int n,
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
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 (