/* nag_ztrcon (f07tuc) Example Program. * * Copyright 2001 Numerical Algorithms Group. * * Mark 7, 2001. */ #include #include #include #include #include #include int main(int argc, char *argv[]) { FILE *fpin, *fpout; /* Scalars */ double rcond; Integer i, j, n, pda; Integer exit_status = 0; Nag_UploType uplo; NagError fail; Nag_OrderType order; /* Arrays */ char nag_enum_arg[40]; Complex *a = 0; #ifdef NAG_COLUMN_MAJOR #define A(I, J) a[(J-1)*pda + I - 1] order = Nag_ColMajor; #else #define A(I, J) a[(I-1)*pda + 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); fprintf(fpout, "nag_ztrcon (f07tuc) Example Program Results\n"); /* Skip heading in data file */ fscanf(fpin, "%*[^\n] "); fscanf(fpin, "%ld%*[^\n] ", &n); #ifdef NAG_COLUMN_MAJOR pda = n; #else pda = n; #endif /* Allocate memory */ if (!(a = NAG_ALLOC(n * n, Complex))) { 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 , %lf )", &A(i, j).re, &A(i, j).im); } fscanf(fpin, "%*[^\n] "); } else { for (i = 1; i <= n; ++i) { for (j = 1; j <= i; ++j) fscanf(fpin, " ( %lf , %lf )", &A(i, j).re, &A(i, j).im); } fscanf(fpin, "%*[^\n] "); } /* Estimate condition number */ /* nag_ztrcon (f07tuc). * Estimate condition number of complex triangular matrix */ nag_ztrcon(order, Nag_OneNorm, uplo, Nag_NonUnitDiag, n, a, pda, &rcond, &fail); if (fail.code != NE_NOERROR) { fprintf(fpout, "Error from nag_ztrcon (f07tuc).\n%s\n", fail.message); exit_status = 1; goto END; } fprintf(fpout, "\n"); /* nag_machine_precision (x02ajc). * The machine precision */ if (rcond >= X02AJC) { fprintf(fpout, "Estimate of condition number =%11.2e\n\n", 1.0/rcond); } else fprintf(fpout, "A is singular to working precision\n"); END: if (fpin != stdin) fclose(fpin); if (fpout != stdout) fclose(fpout); if (a) NAG_FREE(a); return exit_status; }