| 1 | #include <R.h> |
| 2 | #include <Rdefines.h> |
| 3 | #include "sources/connexity.h" |
| 4 | |
| 5 | // explore the connectivity of a graph (NIix = neighborhoods indices) |
| 6 | SEXP getConnectedComponents( |
| 7 | SEXP NIix_ |
| 8 | ) { |
| 9 | // extract NIix list vectors in a jagged array |
| 10 | int n = LENGTH(NIix_); |
| 11 | int* lengthNIix = (int*)malloc(n*sizeof(int)); |
| 12 | int** NIix = (int**)malloc(n*sizeof(int*)); |
| 13 | for (int i=0; i<n; i++) |
| 14 | { |
| 15 | lengthNIix[i] = LENGTH(VECTOR_ELT(NIix_,i)); |
| 16 | SEXP tmp; |
| 17 | PROTECT(tmp = AS_INTEGER(VECTOR_ELT(NIix_,i))); |
| 18 | NIix[i] = (int*)malloc(lengthNIix[i]*sizeof(int)); |
| 19 | for (int j=0; j<lengthNIix[i]; j++) |
| 20 | NIix[i][j] = INTEGER(tmp)[j]; |
| 21 | UNPROTECT(1); |
| 22 | // WARNING: R indices start at 1, |
| 23 | // so we must lower every index right now to avoid future bug |
| 24 | for (int j=0; j<lengthNIix[i]; j++) |
| 25 | NIix[i][j]--; |
| 26 | } |
| 27 | |
| 28 | // Main call (no R libraries) |
| 29 | int* connexComps = getConnectedComponents_core(NIix, lengthNIix, n); |
| 30 | |
| 31 | // free memory |
| 32 | for (int i=0; i<n; i++) |
| 33 | free(NIix[i]); |
| 34 | free(NIix); |
| 35 | free(lengthNIix); |
| 36 | |
| 37 | // transfer result in an R object |
| 38 | SEXP cc; |
| 39 | PROTECT(cc = NEW_INTEGER(n)); |
| 40 | int* pcc = INTEGER_POINTER(cc); |
| 41 | for (int i=0; i<n; i++) |
| 42 | pcc[i] = connexComps[i]; |
| 43 | |
| 44 | // free remaining memory |
| 45 | free(connexComps); |
| 46 | UNPROTECT(1); |
| 47 | |
| 48 | return cc; |
| 49 | } |