Hi everyone! I'm trying to lear how to call external C code in R but even the R help web-page example is drive me crazy.
I copy-paste the example at: http://stat.ethz.ch/R-manual/R-patched/doc/manual/R-exts.html#Interface%20functions%20.C%20and%20.Fortran here is the example: void convolve(double *a, int *na, double *b, int *nb, double *ab) { int i, j, nab = *na + *nb - 1; for(i = 0; i < nab; i++) ab[i] = 0.0; for(i = 0; i < *na; i++) for(j = 0; j < *nb; j++) ab[i + j] += a[i] * b[j]; } called from R by conv <- function(a, b) .C("convolve", as.double(a), as.integer(length(a)), as.double(b), as.integer(length(b)), ab = double(length(a) + length(b) - 1))$ab but using the conv function in simple examples give me trouble: > conv(1:10,2:11) Error in conv(1:10, 2:11) : pairlist object cannot be coerced to double > conv( rnorm(10,10,1) , rnorm(10,11,1) ) Segmentation fault > conv( c(10.53, 8.456, 6.6) , c(10.53, 8.456, 6.6) ) Error in conv(c(10.53, 8.456, 6.6), c(10.53, 8.456, 6.6)) : cannot allocate vector of length 1717986918 > a = c(1.46756, 5.56456, 2.3646) > b = a + 5.4 > conv(a,b) Error in conv(a, b) : cannot coerce type promise to double vector and so on. These results appear if I have only the .c file or if I use gcc -c conv.c to create .o file. I cannot create executable because there is no main(...) in .c file but just the copy-pasted example. Someone knows what is happening to me ? ______________________________________________ [EMAIL PROTECTED] mailing list https://www.stat.math.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
