#include "geompak.h"
FUNCTION c_grdred (grid, tol)
struct GEOGRID *grid; double *tol;
A GEOGRID structure that contains the entire geometric mapping grid.
Tolerance for reducing the density (dimensions) of the geometric mapping grid. Values given for tol are given in units of pixels.
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).
c_grdred() returns
E_SUCC (0) --> successful completion, grid reduced E_FAIL (-1) --> grid cannot be reduced
The c_grdred() call is for C only.