Ricardo Zorzetto Nicoliello Vencio <[EMAIL PROTECTED]> writes: > 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 ?
Looks like you haven't quite understood how to generate a shared library (R CMD SHLIB) and load it dynamically (dyn.load), and then somehow pick up a different convolve entry point (doesn't seem possible with Linux, but you're not tellig us what your system is...). Either that or you managed to confuse R badly through some earlier attempts to load the module. -- O__ ---- Peter Dalgaard Blegdamsvej 3 c/ /'_ --- Dept. of Biostatistics 2200 Cph. N (*) \(*) -- University of Copenhagen Denmark Ph: (+45) 35327918 ~~~~~~~~~~ - ([EMAIL PROTECTED]) FAX: (+45) 35327907 ______________________________________________ [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
