/* nag_dgbmv (f16pbc) Example Program. * * Copyright 2005 Numerical Algorithms Group. * * Mark 8, 2005. */ #include #include #include #include #include int main(void) { /* Scalars */ double alpha, beta; Integer ab_size, exit_status, i, incx, incy, j, kl, ku; Integer m, n, pdab, xlen, ylen; /* Arrays */ double *ab=0, *x=0, *y=0; char nag_enum_arg[40]; /* Nag Types */ NagError fail; Nag_OrderType order; Nag_TransType trans; #ifdef NAG_COLUMN_MAJOR #define AB(I,J) ab[(J-1)*pdab + ku + I - J] order = Nag_ColMajor; #else #define AB(I,J) ab[(I-1)*pdab + kl + J - I] order = Nag_RowMajor; #endif exit_status = 0; INIT_FAIL(fail); Vprintf( "nag_dgbmv (f16pbc) Example Program Results\n\n"); /* Skip heading in data file */ Vscanf("%*[^\n] "); /* Read the problem dimensions */ Vscanf("%ld%ld%ld%ld%*[^\n] ", &m, &n, &kl, &ku); /* Read the transpose parameter */ Vscanf("%s%*[^\n] ", nag_enum_arg); /* nag_enum_name_to_value(x04nac). * Converts NAG enum member name to value */ trans = 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); pdab = kl + ku + 1; #ifdef NAG_COLUMN_MAJOR ab_size = pdab*n; #else ab_size = pdab*m; #endif if (trans == Nag_NoTrans) { xlen = MAX(1, 1 + (n - 1)*ABS(incx)); ylen = MAX(1, 1 + (m - 1)*ABS(incy)); } else { xlen = MAX(1, 1 + (m - 1)*ABS(incx)); ylen = MAX(1, 1 + (n - 1)*ABS(incy)); } if (m > 0 && n > 0) { /* Allocate memory */ if ( !(ab = NAG_ALLOC(ab_size, double)) || !(x = NAG_ALLOC(xlen, double))|| !(y = NAG_ALLOC(ylen, double))) { Vprintf("Allocation failure\n"); exit_status = -1; goto END; } } else { Vprintf("Invalid m or n\n"); exit_status = 1; return exit_status; } /* Input matrix A and vectors x and y */ for (i = 1; i <= m; ++i) { for (j = MAX(1,i-kl); j <= MIN(n,i+ku); ++j) Vscanf("%lf", &AB(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_dgbmv(f16pbc). * real valued band matrix-vector multiply. * */ nag_dgbmv(order, trans, m, n, kl, ku, alpha, ab, pdab, x, incx, beta, y, incy, &fail); if (fail.code != NE_NOERROR) { Vprintf("Error from nag_dgbmv.\n%s\n", fail.message); exit_status = 1; goto END; } /* Print output vector y */ Vprintf("Updated vector y:\n\n"); for (i = 1; i <= ylen; ++i) { Vprintf("%11f\n", y[i-1]); } END: if (ab) NAG_FREE(ab); if (x) NAG_FREE(x); if (y) NAG_FREE(y); return exit_status; }