# griddata¶

griddata creates a regular grid of arbitrarily distributed data triples.

`rmZi = griddata(rvX, rvY, rvZ, rvXi, rvYi)`
`rmZi = griddata(rvX, rvY, rvZ, rvXi, rvYi, nOption)`
`rmZi = griddata(rvX, rvY, rvZ, rvXi, rvYi, ssOption)`

Return Value

rmZi is the interpolated z value matrix for the given rvXi and rvYi coordinates. In case of an error rmZi is an error object (see example).

Parameters

`rvX`

rvX is a real vector with at least 4 elements.

`rvY`

rvY is a real vector with at least 4 elements. The number of points must be identical with rvX.

`rvZ`

rvZ is a real vector with at least 4 elements. The number of points must be identical with rvX.

`rvXi`

rvXi is a real vector with at least one point.

`rvYi`

rvYi is a real vector with at least one point.

`ssOption`

See nOption.

`nOption`

Is one of the following values:

ssOption nOption
“linear” 1 Linear interpolation.
“cubic” 2 cubic spline interpolation.
“tps” oder “thin-plate-spline” 3 Thin-Plate-Spline interpolation.
“poly1” or “plane” 4
“poly2” 5
“poly3” 6
“interp1d-bilinear” 7

Example

If an error occurred, griddata returns an error object (see also error_create).

```def test_griddata()
{
srand(1);
x = rand(100, 1)*15-7.5;
y = rand(100, 1)*15-7.5;
r = sqrt(x.*x + y.*y);
z = sin(r)./r;
xi = linspace(-7.5, 7.5, 40)
yi = xi;
zi = griddata(x, y, z, xi, yi, "thin-plate-spline");
if (type(zi) == "error") {
MessageBoxError(zi.message);
return FALSE;
}
plotxyz(xi, yi, zi);
return TRUE;
}
```

History

Version Description
5.20 New.

id-1546570