griddatan (MATLAB Function Reference)

Data gridding and hypersurface fitting (dimension >= 2)

Syntax

yi = griddatan(X,y,xi)
yi = griddatan(...,'method')

Description

yi = griddatan(X, y, xi) fits a hyper-surface of the form y = f(X) to the data in the (usually) nonuniformly-spaced vectors (X, y). griddatan interpolates this hyper-surface at the points specified by xi to produce yi. xi can be nonuniform.

X is of dimension m-by-n, representing m points in n-D space. y is of dimension m-by-1, representing m values of the hyper-surface f(X). xi is a vector of size p-by-n, representing p points in the n-D space whose surface value is to be fitted. yi is a vector of length p approximating the values f(xi). The hypersurface always goes through the data points (X,y). xi is usually a uniform grid (as produced by meshgrid).

[...] = griddatan(...,'method') defines the type of surface fit to the data, where 'method' is one of:

'linear'
Tessellation-based linear interpolation (default)

'nearest'
Nearest neighbor interpolation

`'linear'`	Tessellation-based linear interpolation (default)
`'nearest'`	Nearest neighbor interpolation

All the methods are based on a Delaunay tessellation of the data.

Note griddatan calls delaunayn, which is based on qhull [1]. For information about qhull, see http://www.geom.umn.edu/software/qhull/. For copyright information, see http://www.geom.umn.edu/software/download/COPYING.html.

Reference

[1] National Science and Technology Research Center for Computation and Visualization of Geometric Structures (The Geometry Center), University of Minnesota. 1993.

griddata3 gsvd