/* nag_zgebrd (f08ksc) Example Program. * * Copyright 2001 Numerical Algorithms Group. * * Mark 7, 2001. */ #include #include #include #include int main(void) { /* Scalars */ Integer i, j, m, n, pda, d_len, e_len, tauq_len, taup_len; Integer exit_status = 0; NagError fail; Nag_OrderType order; /* Arrays */ Complex *a = 0, *taup = 0, *tauq = 0; double *d = 0, *e = 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); printf("nag_zgebrd (f08ksc) Example Program Results\n"); /* Skip heading in data file */ scanf("%*[^\n] "); scanf("%ld%ld%*[^\n] ", &m, &n); #ifdef NAG_COLUMN_MAJOR pda = m; #else pda = n; #endif d_len = MIN(m, n); e_len = MIN(m, n)-1; tauq_len = MIN(m, n); taup_len = MIN(m, n); /* Allocate memory */ if (!(a = NAG_ALLOC(m * n, Complex)) || !(d = NAG_ALLOC(d_len, double)) || !(e = NAG_ALLOC(e_len, double)) || !(taup = NAG_ALLOC(taup_len, Complex)) || !(tauq = NAG_ALLOC(tauq_len, Complex))) { printf("Allocation failure\n"); exit_status = -1; goto END; } /* Read A from data file */ for (i = 1; i <= m; ++i) { for (j = 1; j <= n; ++j) scanf(" ( %lf , %lf )", &A(i, j).re, &A(i, j).im); } scanf("%*[^\n] "); /* Reduce A to bidiagonal form */ /* nag_zgebrd (f08ksc). * Unitary reduction of complex general rectangular matrix * to bidiagonal form */ nag_zgebrd(order, m, n, a, pda, d, e, tauq, taup, &fail); if (fail.code != NE_NOERROR) { printf("Error from nag_zgebrd (f08ksc).\n%s\n", fail.message); exit_status = 1; goto END; } /* Print bidiagonal form */ printf("\nDiagonal\n"); for (i = 1; i <= MIN(m, n); ++i) printf("%9.4f%s", d[i-1], i%8 == 0?"\n":" "); if (m >= n) printf("\nSuper-diagonal\n"); else printf("\nSub-diagonal\n"); for (i = 1; i <= MIN(m, n) - 1; ++i) printf("%9.4f%s", e[i-1], i%8 == 0?"\n":" "); printf("\n"); END: if (a) NAG_FREE(a); if (d) NAG_FREE(d); if (e) NAG_FREE(e); if (taup) NAG_FREE(taup); if (tauq) NAG_FREE(tauq); return exit_status; }