/* nag_zpoequ (f07ftc) Example Program. * * Copyright 2008 Numerical Algorithms Group. * * Mark 23, 2011. */ #include #include #include #include #include #include int main(void) { /* Scalars */ double amax, big, scond, small; Integer i, j, n, pda; Integer exit_status = 0; /* Arrays */ Complex *a = 0; double *s = 0; /* Nag Types */ NagError fail; Nag_OrderType order; #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); printf("nag_zpoequ (f07ftc) Example Program Results\n\n"); /* Skip heading in data file */ scanf("%*[^\n]"); scanf("%ld%*[^\n]", &n); pda = n; /* Allocate memory */ if (!(a = NAG_ALLOC(n * n, Complex)) || !(s = NAG_ALLOC(n, double))) { printf("Allocation failure\n"); exit_status = -1; goto END; } /* Read the upper triangular part of the matrix A from data file */ for (i = 1; i <= n; ++i) for (j = i; j <= n; ++j) scanf(" ( %lf , %lf )", &A(i, j).re, &A(i, j).im); scanf("%*[^\n]"); /* Print the matrix A using nag_gen_complx_mat_print_comp (x04dbc). */ fflush(stdout); nag_gen_complx_mat_print_comp(order, Nag_UpperMatrix, Nag_NonUnitDiag, n, n, a, pda, Nag_BracketForm, "%11.2e", "Matrix A", Nag_IntegerLabels, 0, Nag_IntegerLabels, 0, 80, 0, 0, &fail); if (fail.code != NE_NOERROR) { printf("Error from nag_gen_complx_mat_print_comp (x04dbc).\n%s\n", fail.message); exit_status = 1; goto END; } printf("\n"); /* Compute diagonal scaling factors using nag_zpoequ (f07ftc). */ nag_zpoequ(order, n, a, pda, s, &scond, &amax, &fail); if (fail.code != NE_NOERROR) { printf("Error from nag_zpoequ (f07ftc).\n%s\n", fail.message); exit_status = 1; goto END; } /* Print scond, amax and the scale factors */ printf("scond = %10.1e, amax = %10.1e\n", scond, amax); printf("\nDiagonal scaling factors\n"); for (i = 0; i < n; ++i) printf("%11.1e%s", s[i], i%7 == 6?"\n":" "); printf("\n\n"); /* Compute values close to underflow and overflow using * nag_real_safe_small_number (x02amc), nag_machine_precision (x02ajc) and * nag_real_base (x02bhc) */ small = nag_real_safe_small_number / (nag_machine_precision * nag_real_base); big = 1.0 / small; if (scond < 0.1 || amax < small || amax > big) { /* Scale A */ for (j = 1; j <= n; ++j) for (i = 1; i <= j; ++i) { A(i, j).re *= s[i-1]*s[j-1]; A(i, j).im *= s[i-1]*s[j-1]; } /* Print the scaled matrix using * nag_gen_complx_mat_print_comp (x04dbc). */ fflush(stdout); nag_gen_complx_mat_print_comp(order, Nag_UpperMatrix, Nag_NonUnitDiag, n, n, a, pda, Nag_BracketForm, 0, "Scaled matrix", Nag_IntegerLabels, 0, Nag_IntegerLabels, 0, 80, 0, 0, &fail); if (fail.code != NE_NOERROR) { printf("Error from nag_gen_complx_mat_print_comp (x04dbc).\n%s\n", fail.message); exit_status = 1; goto END; } } END: if (a) NAG_FREE(a); if (s) NAG_FREE(s); return exit_status; } #undef A