similar to: random numbers in C

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 (