csagrid(3) cubic spline approximation


Csagrid is a software package in the ngmath library that implements a cubic spline approximation algorithm to fit a function to input data. The input for the approximation is a set of randomly-spaced data. These data may be one-dimensional, two-dimensional, or three-dimensional.

The output is a set of values at coordinates on a user-specified grid, or at a set of user-specified points (including at a single point).

Functionally equivalent Fortran, C, and NCL interfaces are provided.

Csagrid is based on the work of David Fulker and his package Splpack.


Fortran one-dimensional input

 CSA1S        -  simple entry

 CSA1XS       - expanded entry

Fortran two-dimensional input

 CSA2S        - simple entry, gridded output

 CSA2XS       - expanded entry, gridded output

 CSA2LS       - simple entry, list output

 CSA2LXS      - expanded entry, list output

Fortran three-dimensional input

 CSA3S        - simple entry, gridded output

 CSA3XS       - expanded entry, gridded output

 CSA3LS       - simple entry, list output

 CSA3LXS      - expanded entry, list output

C one-dimensional input

 c_csa1s        -  simple entry

 c_csa1xs       - expanded entry

C two-dimensional input

 c_csa2s        - simple entry, gridded output

 c_csa2xs       - expanded entry, gridded output

 c_csa2ls       - simple entry, list output

 c_csa2lxs      - expanded entry, list output

C three-dimensional input

 c_csa3s        - simple entry, gridded output

 c_csa3xs       - expanded entry, gridded output

 c_csa3ls       - simple entry, list output

 c_csa3lxs      - expanded entry, list output

NCL one-dimensional input

 csa1s        -  simple entry

 csa1xs       - expanded entry

NCL two-dimensional input

 csa2s        - simple entry, gridded output

 csa2xs       - expanded entry, gridded output

 csa2ls       - simple entry, list output

 csa2lxs      - expanded entry, list output

NCL three-dimensional input

 csa3s        - simple entry, gridded output

 csa3xs       - expanded entry, gridded output

 csa3ls       - simple entry, list output

 csa3lxs      - expanded entry, list output


To use Csagrid entries, 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.