Dear all,
This email comes after a discussion on the R-pkg-devel mailing list:
https://stat.ethz.ch/pipermail/r-package-devel/2016q1/000627.html
My purpose was to be able, in two of my packages, to use complex numbers
(create some, addition, multiplication, division, modulus, etc)
directly in a C code that is called from R (using the .C interface).
Note that these complex numbers might not come from R but could be
created and used directly in my C code, that will then output (via
pointers)
real (I mean double) values back to R (via the .C interface). I could
also send from R these complex numbers via the .C interface.
A very simple example of such a function called from R via the .C
interface could be the following:
#include <R.h>
#include "Rmath.h"
extern "C" {
void Cfunc(complex double *var) {
double _Complex z = 1.0 + 2.0 * _Complex_I;
var[0] = z + exp(var[0]);
return;
}}
I could call this function from R as follows:
.C(1i)
No problem so far when I use such a function in a package that is
compiled under Linux. But this will not work under windows (see the
discussion
on the R-pkg-devel list). So what I did to make everything work under
Windows also was to include in the src/ directory of my package the
source files
from the RcppFaddeeva package. Then I would modify the function above as
follows:
#include <R.h>
#include "Rmath.h"
#include "libraries/callFaddeeva.cpp"
#include "libraries/Faddeeva.cpp"
#include "libraries/RcppExports.cpp"
extern "C" {
void Cfunc(complex double *var) {
cmplx z = C(1.0, 2.0);
var[0] = z + cexp(var[0]);
return;
}}
Maybe there is a way not to include all the Faddeeva source files in my
packages? But I do not know how to do it.
Best regards,
Pierre L.
--
Pierre Lafaye de Micheaux
Adresse courrier:
Université de Montréal
Pavillon André-Aisenstadt
Département de Mathématiques et Statistique
CP 6128 Succursale Centre-ville
Montréal Qc H3C 3J7
CANADA
Adresse physique:
Département de Mathématiques et Statistique
Bureau 4249, Pavillon André-Aisenstadt
2920, chemin de la Tour
Montréal, Québec H3T 1J4
CANADA
Tél.: (00-1) 514-343-6607 / Fax: (00-1) 514-343-5700
laf...@dms.umontreal.ca
http://www.biostatisticien.eu
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