c_grdred - Reduces the dimensions of a geometric mapping grid

SYNTAX

#include "geompak.h"

FUNCTION c_grdred (grid, tol)

     struct GEOGRID       *grid;
     double               *tol;

PARAMETERS

grid (input/output, GEOGRID)

A GEOGRID structure that contains the entire geometric mapping grid.

tol (input, double)

Tolerance for reducing the density (dimensions) of the geometric mapping grid. Values given for tol are given in units of pixels.

DESCRIPTION

c_grdred() discards rows and columns of the geometric mapping grid that are within told, the tolerance of linear approximation across neighboring rows and columns. The resulting geometric mapping grid is stored back into the grid parameter. Note that the dimensions of the grid must be 127 rows by 127 columns prior to grid reduction (on input).

RETURN VALUE

c_grdred() returns

     E_SUCC (0) --> successful completion, grid reduced
     E_FAIL (-1) --> grid cannot be reduced

SPECIAL CONSIDERATIONS:

The c_grdred() call is for C only.