OS/2 Shareware BBS: Science/Science.zip/gmt_os2.zip/src/grdclip.c

C/C++ Source or Header | 1995-03-13 | 4.3 KB | 153 lines

/*--------------------------------------------------------------------
 *    The GMT-system:    @(#)grdclip.c    2.16  3/13/95
 *
 *    Copyright (c) 1991-1995 by P. Wessel and W. H. F. Smith
 *    See README file for copying and redistribution conditions.
 *--------------------------------------------------------------------*/
/*
   grdclip read a grdfile and sets all values < the user-supplied
   lower limit to the value <below>, and all values > the user-
   supplied upper limit to the value <above>.  above/below can
   be any number of gmt_NaN.

   WHF Smith, 22 Aug 88
   Modified for v2.0 4/26/91 P.Wessel

 */


#include "gmt.h"

float *data;

main (argc, argv)
int argc;
char **argv; {

    int    error, set_above, set_below, i, nxy, n_above, n_below, n, dummy[4];
    float    above, below, low, high;
    char *infile, *outfile;
    struct GRD_HEADER header;

    argc = gmt_begin (argc, argv);

    error = set_above = set_below = FALSE;
    n_above = n_below = 0;
    low = high = 0.0;
    dummy[3] = dummy[2] = dummy[1] = dummy[0] = 0;

    for (i = 1; i < argc; i++) {
        if (argv[i][0] == '-') {
            switch (argv[i][1]) {
                /* Common parameters */

                case 'V':
                case '\0':
                    error += get_common_args (argv[i], 0, 0, 0, 0);
                    break;

                /* Supplemental parameters */

                case 'A':
                    set_above = TRUE;
                    n = sscanf (&argv[i][2], "%f/%f", &high, &above);
                    if (n == 0) {
                        fprintf (stderr, "%s: GMT SYNTAX ERROR -A option.  Correct syntax:\n", gmt_program);
                        fprintf (stderr, "\t-A<high>/<above>, <above> may be set to NaN\n");
                        error = TRUE;
                    }
                    else if (n == 1) above = gmt_NaN;
                    break;
                case 'B':
                    set_below = TRUE;
                    n = sscanf (&argv[i][2], "%f/%f", &low, &below);
                    if (n == 0) {
                        fprintf (stderr, "%s: GMT SYNTAX ERROR -B option.  Correct syntax:\n", gmt_program);
                        fprintf (stderr, "\t-B<low>/<below>, <below> may be set to NaN\n");
                        error = TRUE;
                    }
                    else if (n == 1) below = gmt_NaN;
                    break;
                case 'G':
                    outfile = &argv[i][2];
                    break;

                default:
                    error = TRUE;
                    gmt_default_error (argv[i][1]);
                    break;
            }
        }
        else
            infile = argv[i];
    }

    if (gmt_quick || argc == 1) {
        fprintf (stderr, "grdclip %s - Clipping of range in grdfiles\n\n", GMT_VERSION);
        fprintf (stderr, "usage: grdclip <input_grdfile> -G<output_grdfile>\n");
        fprintf (stderr, "\t[-A<high/above>] [-B<low/below>] [-V]\n");

        if (gmt_quick) exit (-1);

        fprintf (stderr, "\tYou must choose at least one of A or B.\n");
        fprintf (stderr, "\t-G name of output grid.\n");
        fprintf (stderr, "\n\tOPTIONS:\n");
        fprintf (stderr, "\t-A will set all data > high to the <above> value.\n");
        fprintf (stderr, "\t-B will set all data < low to the <below> value.\n");
        fprintf (stderr, "\t   above/below can be any number including gmt_NaN\n");
        explain_option ('V');
        exit (-1);
    }

    if (!outfile) {
        fprintf (stderr, "%s: GMT SYNTAX ERROR -G option:.  Must specify output file\n", gmt_program);
        error++;
    }
    if (!infile) {
        fprintf (stderr, "%s: GMT SYNTAX ERROR:.  Must specify input file\n", gmt_program);
        error++;
    }

    if (error) exit (-1);

    if (read_grd_info (infile, &header)) {
        fprintf (stderr, "grdclip: Error opening file %s\n", infile);
        exit (-1);
    }

    grd_init (&header, argc, argv, TRUE);

    nxy = header.nx * header.ny;
    data = (float *) memory (CNULL, nxy, sizeof (float), "grdclip");

    if (read_grd (infile, &header, data, 0.0, 0.0, 0.0, 0.0, dummy, FALSE)) {
        fprintf (stderr, "grdclip: Error reading file %s\n", infile);
        exit (-1);
    }

    for (i = 0; i < nxy; i++) {
        if (set_above && (!bad_float ((double)data[i])) && data[i] > high) {
            data[i] = above;
            n_above++;
        }
        else if (set_below && (!bad_float ((double)data[i])) && data[i] < low) {
            data[i] = below;
            n_below++;
        }
    }

    if (write_grd (outfile, &header, data, 0.0, 0.0, 0.0, 0.0, dummy, FALSE)) {
        fprintf (stderr, "grdclip: Error writing file %s\n", infile);
        exit (-1);
    }

    free ((char *) data);

    if (gmtdefs.verbose) {
        if (set_below) fprintf (stderr, "%d values < %g set to %g\n", n_below, low, below);
        if (set_above) fprintf (stderr, "%d values > %g set to %g\n", n_above, high, above);
    }

    gmt_end (argc, argv);
}