c_nngetslopes - retrieve the slope at a specified coordinate.

       To use c_nngetslopes, load the NCAR Graphics library ngmath.

       Copyright (C) 2000
       University Corporation for Atmospheric Research

       The use of this Software is governed by a License Agreement.

UNIX                                             March 1997-1998                           c_nngetslopes(3NCARG)

       row         A  subscript  indexing  the first dimensioned variable in the 2D grid array returned from the
                   most recent call to c_natgrids.

       column      A subscript indexing the second dimensioned variable in the 2D grid array returned  from  the
                   most recent call to c_natgrids.

       slope       *slope  is  the slope at the grid point z[i,j], where z is the output grid in the most recent
                   call to c_natgrids.

       ier         An error value. If *ier is 0, then no errors were detected. If *ier is non-zero,  then  refer
                   to the man page for natgrid_errors for details.

       void c_nngetslopes(int, int, float *, int *);

       c_nngetslopes - retrieve the slope at a specified coordinate.

       natgrid, natgrid_params, c_nngetaspects.

       Complete documentation for Natgrid is available at URL
       http://ngwww.ucar.edu/ngdoc/ng/ngmath/natgrid/nnhome.html

       c_nngetslopes (row, column, slope, ier);

       This  routine  allows  you  to  retrieve the current value of Natgrid parameters.  For a complete list of
       parameters available in this utility, see the natgrid_params man page.