/* nag_dpptrf (f07gdc) Example Program. * * Copyright 2001 Numerical Algorithms Group. * * Mark 7, 2001. */ #include #include #include #include #include int main(int argc, char *argv[]) { FILE *fpin, *fpout; char *outfile = 0; /* Scalars */ Integer ap_len, i, j, n; Integer exit_status = 0; Nag_UploType uplo; NagError fail; Nag_OrderType order; /* Arrays */ char nag_enum_arg[40]; double *ap = 0; #ifdef NAG_COLUMN_MAJOR #define A_UPPER(I, J) ap[J*(J-1)/2 + I - 1] #define A_LOWER(I, J) ap[(2*n-J)*(J-1)/2 + I - 1] order = Nag_ColMajor; #else #define A_LOWER(I, J) ap[I*(I-1)/2 + J - 1] #define A_UPPER(I, J) ap[(2*n-I)*(I-1)/2 + J - 1] order = Nag_RowMajor; #endif INIT_FAIL(fail); /* Check for command-line IO options */ fpin = nag_example_file_io(argc, argv, "-data", NULL); fpout = nag_example_file_io(argc, argv, "-results", NULL); (void) nag_example_file_io(argc, argv, "-nag_write", &outfile); fprintf(fpout, "nag_dpptrf (f07gdc) Example Program Results\n\n"); /* Skip heading in data file */ fscanf(fpin, "%*[^\n] "); fscanf(fpin, "%ld%*[^\n] ", &n); ap_len = n*(n+1)/2; /* Allocate memory */ if (!(ap = NAG_ALLOC(ap_len, double))) { fprintf(fpout, "Allocation failure\n"); exit_status = -1; goto END; } /* Read A from data file */ fscanf(fpin, " %s%*[^\n] ", nag_enum_arg); /* nag_enum_name_to_value(x04nac). * Converts NAG enum member name to value */ uplo = (Nag_UploType) nag_enum_name_to_value(nag_enum_arg); if (uplo == Nag_Upper) { for (i = 1; i <= n; ++i) { for (j = i; j <= n; ++j) fscanf(fpin, "%lf", &A_UPPER(i, j)); } fscanf(fpin, "%*[^\n] "); } else { for (i = 1; i <= n; ++i) { for (j = 1; j <= i; ++j) fscanf(fpin, "%lf", &A_LOWER(i, j)); } fscanf(fpin, "%*[^\n] "); } /* Factorize A */ /* nag_dpptrf (f07gdc). * Cholesky factorization of real symmetric * positive-definite matrix, packed storage */ nag_dpptrf(order, uplo, n, ap, &fail); if (fail.code != NE_NOERROR) { fprintf(fpout, "Error from nag_dpptrf (f07gdc).\n%s\n", fail.message); exit_status = 1; goto END; } /* Print factor */ /* nag_pack_real_mat_print (x04ccc). * Print real packed triangular matrix (easy-to-use) */ if (outfile) fclose(fpout); nag_pack_real_mat_print(order, uplo, Nag_NonUnitDiag, n, ap, "Factor", outfile, &fail); if (outfile && !(fpout = fopen(outfile, "a"))) { exit_status = 2; goto END; } if (fail.code != NE_NOERROR) { fprintf(fpout, "Error from nag_pack_real_mat_print (x04ccc).\n%s\n", fail.message); exit_status = 1; goto END; } END: if (fpin != stdin) fclose(fpin); if (fpout != stdout) fclose(fpout); if (ap) NAG_FREE(ap); return exit_status; }