# ncl_cssgrid man page

CSSGRID — tension spline interpolation on a sphere.

## Synopsis

CALL CSSGRID (N, RLAT, RLON, F, NI, NJ, PLAT, PLON, FF, IWK, RWK, IER)

## Description

- N
(integer,input) The number of input data points (N > 2).

- RLAT
(real, input) An array containing the latitudes of the input data, expressed in degrees. The first three points must not be collinear (lie on a common great circle).

- RLON
(real, input) An array containing the longitudes of the input data, expressed in degrees.

- F
(real, input) An array containing data values. F(I) is a functional value at (RLAT(I),RLON(I)) for I = 1 to N.

- NI
(integer, input) The number of rows in the uniform output grid. NI can be 1.

- NJ
(integer, input) The number of columns in the uniform output grid. NJ can be 1.

- PLAT
(real, intput) An array of length NI containing the latitudes the output grid lines. The values in PLAT should be in degrees.

- PLON
(real, intput) An array of length NJ containing the longitudes the output grid lines. The value in PLON should be in degrees.

- FF
(real, output) An NI by NJ array containing the desired interpolated values. FF(I,J) is the interpolated value at the coordinate specified by PLAT(I) and PLON(J) for I = 1 to NI and J = 1 to NJ.

- IWK
(integer, input) An integer workspace of length 27*N.

- RWK
(double precision, input) A work array dimensioned for 13*N. Note that RWK must be typed DOUBLE PRECISION.

- IER
(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 man page for cssgrid_errors for details.

## Usage

CSSGRID is called to find an interpolating tension spline for data randomly positioned on a sphere.

## Access

To use CSSGRID, load the NCAR Graphics library ngmath.

## See Also

css_overview, csstri, cssgrid_errors

Complete documentation for Cssgrid is available at URL

http://ngwww.ucar.edu/ngdoc/ng/ngmath/cssgrid/csshome.html

## Copyright

Copyright (C) 2000

University Corporation for Atmospheric Research

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