# ncl_shgrid man page

SHGRID — interpolate random data in 3-space using a modified Shepard's algorithm

## Synopsis

CALL SHGRID (N, X, Y, Z, F, NXO, NYO, NZO, XO, YO, ZO,

FF, IWK, RWK, IER)

## Description

- N
(integer,input) The number of input data points (N > 9).

- X
(real, input) An array containing the X coordinates of the input data points. X is dimensioned for N.

- Y
(real, input) An array containing the Y coordinates of the input data points. Y is dimensioned for N.

- Z
(real, input) An array containing the Z coordinates of the input data points. Z is dimensioned for N.

- F
(real, input) Array dimensioned for N containing data values. F(I) is a functional value at (X(I),Y(I),Z(I)) for I = 1 to N.

- NXO
(integer, input) The number of X coordinate values in the output grid.

- NYO
(integer, input) The number of Y coordinate values in the output grid.

- NZO
(integer, input) The number of Z coordinate values in the output grid.

- XO
(real, input) An array dimensioned for NXO containing the X coordinates of the output surface.

- YO
(real, input) An array dimensioned for NYO containing the Y coordinates of the output surface.

- ZO
(real, input) An array dimensioned for NZO containing the Y coordinates of the output surface.

- FF
(real, output) An array dimensioned for NXO x NYO x NZO containing the calculated function values for the output function. FF(I,J,K) is the calculated functional value at (XO(I), YO(J), ZO(K)) for I=1,NXO and J=1,NYO and K=1,NZO.

- IRK
(integer, input) An integer workspace of length at least 2*N.

- RWK
(real, input) A work array dimensioned for 11*N+6.

- 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 shgrid_errors for details.

## Usage

SHGRID is called to interpolate randomly spaced data in 3-space. SHGRID uses a modified Shepard's algorithm to construct an interpolatory surface.

## Access

To use SHGRID, load the NCAR Graphics library ngmath.

## See Also

shgrid_params, shseti, shgeti, shgetnp.

Complete documentation for Shgrid is available at URL

http://ngwww.ucar.edu/ngdoc/ng/ngmath/shgrid/shhome.html

## Copyright

Copyright (C) 2000

University Corporation for Atmospheric Research

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