/* nag_zupgtr (f08gtc) Example Program. * * Copyright 2001 Numerical Algorithms Group. * * Mark 7, 2001. */ #include #include #include #include #include int main(void) { /* Scalars */ Integer ap_len, i, j, n, pdz, d_len, e_len, tau_len; Integer exit_status=0; NagError fail; Nag_UploType uplo; Nag_OrderType order; /* Arrays */ char uplo_char[2]; Complex *ap=0, *tau=0, *z=0; double *d=0, *e=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); Vprintf("nag_zupgtr (f08gtc) Example Program Results\n\n"); /* Skip heading in data file */ Vscanf("%*[^\n] "); Vscanf("%ld%*[^\n] ", &n); #ifdef NAG_COLUMN_MAJOR pdz = n; #else pdz = n; #endif ap_len = n*(n+1)/2; tau_len = n-1; d_len = n; e_len = n-1; /* Allocate memory */ if ( !(ap = NAG_ALLOC(ap_len, Complex)) || !(d = NAG_ALLOC(d_len, double)) || !(e = NAG_ALLOC(e_len, double)) || !(tau = NAG_ALLOC(tau_len, Complex)) || !(z = NAG_ALLOC(n * n, Complex)) ) { Vprintf("Allocation failure\n"); exit_status = -1; goto END; } /* Read A from data file */ Vscanf(" ' %1s '%*[^\n] ", uplo_char); if (*(unsigned char *)uplo_char == 'L') uplo = Nag_Lower; else if (*(unsigned char *)uplo_char == 'U') uplo = Nag_Upper; else { Vprintf("Unrecognised character for Nag_UploType type\n"); exit_status = -1; goto END; } if (uplo == Nag_Upper) { for (i = 1; i <= n; ++i) { for (j = i; j <= n; ++j) { Vscanf(" ( %lf , %lf )", &A_UPPER(i,j).re, &A_UPPER(i,j).im); } } Vscanf("%*[^\n] "); } else { for (i = 1; i <= n; ++i) { for (j = 1; j <= i; ++j) { Vscanf(" ( %lf , %lf )", &A_LOWER(i,j).re, &A_LOWER(i,j).im); } } Vscanf("%*[^\n] "); } /* Reduce A to tridiagonal form T = (Q**H)*A*Q */ /* nag_zhptrd (f08gsc). * Unitary reduction of complex Hermitian matrix to real * symmetric tridiagonal form, packed storage */ nag_zhptrd(order, uplo, n, ap, d, e, tau, &fail); if (fail.code != NE_NOERROR) { Vprintf("Error from nag_zhptrd (f08gsc).\n%s\n", fail.message); exit_status = 1; } /* Form Q explicitly, storing the result in Z */ /* nag_zupgtr (f08gtc). * Generate unitary transformation matrix from reduction to * tridiagonal form determined by nag_zhptrd (f08gsc) */ nag_zupgtr(order, uplo, n, ap, tau, z, pdz, &fail); if (fail.code != NE_NOERROR) { Vprintf("Error from nag_zupgtr (f08gtc).\n%s\n", fail.message); exit_status = 1; goto END; } /* Calculate all the eigenvalues and eigenvectors of A */ /* nag_zsteqr (f08jsc). * All eigenvalues and eigenvectors of real symmetric * tridiagonal matrix, reduced from complex Hermitian * matrix, using implicit QL or QR */ nag_zsteqr(order, Nag_UpdateZ, n, d, e, z, pdz, &fail); if (fail.code != NE_NOERROR) { Vprintf("Error from nag_zsteqr (f08jsc).\n%s\n", fail.message); exit_status = 1; goto END; } /* Print eigenvalues and eigenvectors */ Vprintf("Eigenvalues\n"); for (i = 1; i <= n; ++i) Vprintf("%8.4f%s", d[i-1], i%8==0 ?"\n":" "); Vprintf("\n\n"); /* nag_gen_complx_mat_print_comp (x04dbc). * Print complex general matrix (comprehensive) */ nag_gen_complx_mat_print_comp(order, Nag_GeneralMatrix, Nag_NonUnitDiag, n, n, z, pdz, Nag_BracketForm, "%7.4f", "Eigenvectors", Nag_IntegerLabels, 0, Nag_IntegerLabels, 0, 80, 0, 0, &fail); if (fail.code != NE_NOERROR) { Vprintf("Error from nag_gen_complx_mat_print_comp (x04dbc).\n%s\n", fail.message); exit_status = 1; goto END; } END: if (ap) NAG_FREE(ap); if (d) NAG_FREE(d); if (e) NAG_FREE(e); if (tau) NAG_FREE(tau); if (z) NAG_FREE(z); return exit_status; }