/* nag_dsymv (f16pcc) Example Program. * * Copyright 2005 Numerical Algorithms Group. * * Mark 8, 2005. */ #include #include #include #include #include int main(void) { /* Scalars */ double alpha, beta; Integer exit_status, i, incx, incy, j, n, pda, xlen, ylen; /* Arrays */ double *a=0, *x=0, *y=0; char nag_enum_arg[40]; /* Nag Types */ NagError fail; Nag_OrderType order; Nag_UploType uplo; #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 exit_status = 0; INIT_FAIL(fail); Vprintf( "nag_dsymv (f16pcc) Example Program Results\n\n"); /* Skip heading in data file */ Vscanf("%*[^\n] "); /* Read the problem dimension */ Vscanf("%ld%*[^\n] ", &n); /* Read uplo */ Vscanf("%s%*[^\n] ", nag_enum_arg); /* nag_enum_name_to_value(x04nac). * Converts NAG enum member name to value */ uplo = nag_enum_name_to_value(nag_enum_arg); /* Read scalar parameters */ Vscanf("%lf%lf%*[^\n] ", &alpha, &beta); /* Read increment parameters */ Vscanf("%ld%ld%*[^\n] ", &incx, &incy); pda = n; xlen = MAX(1, 1 + (n - 1)*ABS(incx)); ylen = MAX(1, 1 + (n - 1)*ABS(incy)); if (n > 0) { /* Allocate memory */ if ( !(a = NAG_ALLOC(n*pda, double)) || !(x = NAG_ALLOC(xlen, double)) || !(y = NAG_ALLOC(ylen, double)) ) { Vprintf("Allocation failure\n"); exit_status = -1; goto END; } } else { Vprintf("Invalid n\n"); exit_status = 1; return exit_status; } /* Input the matrix A and vectors x and y */ if (uplo == Nag_Upper) { for (i = 1; i <= n; ++i) { for (j = i; j <= n; ++j) Vscanf("%lf", &A(i,j)); Vscanf("%*[^\n] "); } } else { for (i = 1; i <= n; ++i) { for (j = 1; j <= i; ++j) Vscanf("%lf", &A(i,j)); Vscanf("%*[^\n] "); } } for (i = 1; i <= xlen; ++i) Vscanf("%lf%*[^\n] ", &x[i - 1]); for (i = 1; i <= ylen; ++i) Vscanf("%lf%*[^\n] ", &y[i - 1]); /* nag_dsymv(f16pcc). * Symmetric matrix-vector multiply. * */ nag_dsymv(order, uplo, n, alpha, a, pda, x, incx, beta, y, incy, &fail ); if (fail.code != NE_NOERROR) { Vprintf("Error from nag_dsymv.\n%s\n", fail.message); exit_status = 1; goto END; } /* Print output vector y */ Vprintf("%s\n", " y"); for (i = 1; i <= ylen; ++i) { Vprintf("%11f\n", y[i-1]); } END: if (a) NAG_FREE(a); if (x) NAG_FREE(x); if (y) NAG_FREE(y); return exit_status; }