1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
|
// This is from 'Writing R Extensions' section 5.10.1
// BUT slowed down by using REAL() on each access which proves to be rather costly
#include <R.h>
#include <Rdefines.h>
SEXP convolve7(SEXP a, SEXP b)
{
int i, j, na, nb, nab;
SEXP ab;
PROTECT(a = AS_NUMERIC(a));
PROTECT(b = AS_NUMERIC(b));
na = LENGTH(a); nb = LENGTH(b); nab = na + nb - 1;
PROTECT(ab = NEW_NUMERIC(nab));
for(i = 0; i < nab; i++) REAL(ab)[i] = 0.0;
for(i = 0; i < na; i++)
for(j = 0; j < nb; j++) REAL(ab)[i + j] += REAL(a)[i] * REAL(b)[j];
UNPROTECT(3);
return(ab);
}
#include "loopmacro.h"
LOOPMACRO_C(convolve7)
|
