bionic (3) c_csa2s.3NCARG.gz

Provided by: libncarg-dev_6.4.0-9_amd64 bug

NAME
       c_csa2s - cubic spline approximation, simple entry for two-dimensional input, gridded output


FUNCTION PROTOTYPE
       float *c_csa2s(int, float [], float [], float [], int [],
                      int, int, float [], float [], int *);


SYNOPSIS
       int c_csa2s(int n, float xi[], float yi[], float zi[], int knots[2],
                   int no, int mo, float xo[], float yo[], int *ier);


DESCRIPTION
       n           (integer,input)  The  number  of  input data points. It must be that n is greater than 3 and,
                   depending on the size of knots below, n may have to be larger.

       xi          (real, input) An array dimensioned for n containing the X coordinate  values  for  the  input
                   function.

       yi          (real,  input)  An  array  dimensioned for n containing the Y coordinate values for the input
                   function.

       zi          (real, input) An array containing the functional values of the input function -- zi[k] is the
                   functional value at (xi[k], yi[k]) for k=0,n-1.

       knots       (integer,  input) The number of knots to be used in each coordinate direction in constructing
                   the approximation spline.  knots[0] and knots[1] must be at least 4. The larger the value for
                   knots,  the  closer  the  approximated  curve will come to passing through the input function
                   values.

       no          (integer, input) The number of X coordinate values to be calculated for the output surface.

       mo          (integer, input) The number of Y coordinate values to be calculated for the output surface.

       xo          (real, input) An array dimensioned for no containing the X coordinates of the output grid.

       yo          (real, output) An array dimensioned for mo containing the Y coordinates of the output grid.

       ier         (pointer to integer, output) An error return value. If *ier is returned as 0, then no  errors
                   were  detected.  If  *ier  is  non-zero,  then refer to the error list in the error table for
                   details.


USAGE
       c_csa2s is called to find an approximating cubic spline surface for two-dimensional input  data.  If  you
       want  to weight the input data values, calculate derivatives, or handle data sparse areas specially, then
       you will need to use c_csa2xs.

       c_csa2s returns a pointer to a linear array of data that is the approximated  grid  stored  in  row-major
       order. That is, if out is declared as

         float *out;

       and we set:

         out = c_csa2s(n, x, y, z, knots, no, mo, xo, yo, &ier);

       then  out[i*mo+j]  is  the approximated function value at coordinate point (xo[i], yo[j]) for 0 <= i < no
       and 0 <= j < mo. The space for out is allocated internal to c_csa2s and is no * mo floats in size.


ACCESS
       To use c_csa2s, load the NCAR Graphics library ngmath.


SEE ALSO
       csagrid, c_csa2xs, c_csa2ls, c_csa2lxs

       Complete documentation for Csagrid is available at URL
       http://ngwww.ucar.edu/ngdoc/ng/ngmath/csagrid/csahome.html


       Copyright (C) 2000
       University Corporation for Atmospheric Research

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