# ncl_c_dspnt2d man page

c_dspnt2d — Interpolate at a single point (or points) in 2D in single precision

## Function Prototype

```
void c_dspnt2d(int, double [], double [], double [],
int, double [], double [], double *, int *);
```

## Synopsis

```
void c_dspnt2d (int n, double x[], double y[], double z[],
int m, double xo[], double yo[], double zo, int *ier);
```

## Description

- n
- The number of input data points.
- x
- An array containing the X coordinates of the input data points.
- y
- An array containing the Y coordinates of the input data points.
- z
- An array containing the functional values of the input data points. That is, z[l] is the value of the input function at coordinate (x[l],y[l]), for 0 <= l < n .
- m
- The number of output data points (this may be "1").
- xo
- An array of dimension m containing the X coordinates of the output data. The values in xo may be in any order.
- yo
- An array of dimension m containing the Y coordinates of the output data. The values in xo may be in any order.
- zo
- A pointer to a double. Space for m doubles is allocated for zo by dspnt2d. zo[i] is the interpolated value at point (xo[i],yo[i]) for 0 <= i < n .
- ier
- 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 dsgrid_errors.

## Usage

This function is called when you want to interpolate 2D data at an individual point or points.

## Access

To use c_dspnt2d, load the NCAR Graphics library ngmath.

## See Also

dsgrid, dsgrid_params.

Complete documentation for Dsgrid is available at URL

http://ngwww.ucar.edu/ngdoc/ng/ngmath/d…

## Copyright

Copyright (C) 2000

University Corporation for Atmospheric Research

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

## Info

NCAR GRAPHICS September 1997-1998