Converting 3D data to 2D

I have a 50x4 matrix with the columns being x, y, z, and a value. I want to average each x,y point through the z to convert my 3D data to a 2D.

[Walter Roberson]

Does your data form a regular grid, perhaps 5 x 5 x 2 ?

Or is it scattered data that is not on a grid?

[Josh K]

It is a 5 x 5 x 2. I eventually want to read in much larger data sets but I want to get a working code for this size first.

Answer 1

[Jos (10584)]

So, you want to ignore the z, and average the values for each specific combination of (x,y)?

xyzv = [1 1 1 10 ; 1 1 2 20 ; 1 2 3 30 ; 1 2 5 40 ; 2 2 4 10]  % test data
[xy,~,j] = unique(xyzv(:,[1 2]),'rows')  % unique combinations of (x,y)
xyv = [xy accumarray(j,xyzv(:,4),[size(xy,1),1],@mean)]  % ignore z, average v

[Josh K]

Works great! Thank you!