Hi,
Below I have a mickey-mouse example using Oleg Sklyar's wonderful inline
package.
The question I have is, how do I return multiple values, say in a list?
Inside the C code, I've also calculated 'sum'. How do I return this along with
'res'?
Ultimately, I want to return multiple matrix results. Thanks in advance for
any code snipplets/advice!
Regards,
Ken
#
--------------------------------------------------------------------------------------------------------------------------
> my.mat
[,1] [,2] [,3]
[1,] 1.5 4.5 7.5
[2,] 2.5 5.5 8.5
[3,] 3.5 6.5 9.5
> funx( a=my.mat )
[,1] [,2] [,3]
[1,] -1.5 -4.5 -7.5
[2,] -2.5 -5.5 -8.5
[3,] -3.5 -6.5 -9.5
>
#
--------------------------------------------------------------------------------------------------------------------------
library( inline )
c.code <- "
SEXP res;
int nprotect = 0, nx, ny, x, y;
double *dptr, *resptr, sum;
PROTECT(res = Rf_duplicate(a)); nprotect++;
nx = INTEGER(GET_DIM(a))[0];
ny = INTEGER(GET_DIM(a))[1];
dptr = REAL(a);
resptr = REAL( res );
sum = 0.0;
for (x = 0; x < nx; x++)
for (y = 0; y < ny; y++)
{
resptr[ x + y*nx ] = -dptr[ x + y*nx ];
sum += -dptr[ x + y*nx ];
}
UNPROTECT(nprotect);
return res;
"
funx <- cfunction(signature(a="array"), c.code)
# test run
my.mat <- matrix( 0.5 + 1:9, nrow=3, ncol=3 )
funx( a=my.mat)
______________________________________________
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
