scatstat2 documentation

The scatstat2 function returns statistical values of all points within a given radius of each value. This is similar to taking a moving mean, but points do not need to be equally spaced.

See also scatstat1.

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zbar = scatstat2(x,y,z,radius)
zbar = scatstat2(x,y,z,radius,fun)
ybar = scatstat1(...,options)


zbar = scatstat2(x,y,z,radius) returns the mean of all z values within specified radius at each point (x,y).

zbar = scatstat2(x,y,z,radius,fun) applies any function fun to z values, default fun is @mean, but it could be anything you want, even your own anonymous function.

zbar = scatstat2(...,options) allows any options that the function accepts. For example, 'omitnan'.

Example: Local median

Consider this noisy data set of 5000 scattered points:

N = 5000;
x = randi(750,N,1);
y = randi(750,N,1);

% z contains *real* structure, plus lots of noise:
z = sind(x) + cosd(y) + 3*randn(size(x));

axis image
title 'noisy scattered 2D data'

It almost looks like there's nothing there but noise. Filter out the high-frequency noise by taking the local median within a 75 unit radius:

z_median = scatstat2(x,y,z,75,@median);

axis image
title 'local median'

Author info:

This function was written by Chad A. Greene of the University of Texas at Austin's Institute for Geophysics (UTIG), June 2016.