/* nag_dgbmv (f16pbc) Example Program. * * Copyright 2005 Numerical Algorithms Group. * * Mark 8, 2005. */ #include #include #include #include #include int main(int argc, char *argv[]) { FILE *fpin, *fpout; /* 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); /* Check for command-line IO options */ fpin = nag_example_file_io(argc, argv, "-data", NULL); fpout = nag_example_file_io(argc, argv, "-results", NULL); fprintf(fpout, "nag_dgbmv (f16pbc) Example Program Results\n\n"); /* Skip heading in data file */ fscanf(fpin, "%*[^\n] "); /* Read the problem dimensions */ fscanf(fpin, "%ld%ld%ld%ld%*[^\n] ", &m, &n, &kl, &ku); /* Read the transpose parameter */ fscanf(fpin, "%s%*[^\n] ", nag_enum_arg); /* nag_enum_name_to_value(x04nac). * Converts NAG enum member name to value */ trans = (Nag_TransType) nag_enum_name_to_value(nag_enum_arg); /* Read scalar parameters */ fscanf(fpin, "%lf %lf%*[^\n] ", &alpha, &beta); /* Read increment parameters */ fscanf(fpin, "%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))) { fprintf(fpout, "Allocation failure\n"); exit_status = -1; goto END; } } else { fprintf(fpout, "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) fscanf(fpin, "%lf", &AB(i, j)); fscanf(fpin, "%*[^\n] "); } for (i = 1; i <= xlen; ++i) fscanf(fpin, "%lf%*[^\n] ", &x[i - 1]); for (i = 1; i <= ylen; ++i) fscanf(fpin, "%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) { fprintf(fpout, "Error from nag_dgbmv.\n%s\n", fail.message); exit_status = 1; goto END; } /* Print output vector y */ fprintf(fpout, "Updated vector y:\n\n"); for (i = 1; i <= ylen; ++i) { fprintf(fpout, "%11f\n", y[i-1]); } END: if (fpin != stdin) fclose(fpin); if (fpout != stdout) fclose(fpout); if (ab) NAG_FREE(ab); if (x) NAG_FREE(x); if (y) NAG_FREE(y); return exit_status; }