Get bin label associated with 2D histogram of x,y data

Hello,

I am looking for a way to extract the bin labels from a large matrix of x and y coordinates. So the basic form of it would look like this:

A(:,1) = randi([50 550],500,1); % random x coord

A(:,2) = randi([50 250],500,1); % random y coord

Hist = hist3(A, [25 25]);

Is it possible to get the bin label associated with each of my 500 datapoints? Bigger picture is that all these coordinates in fact have some value and I want to average all these values for the bin they were found in based on their coordinates, before processing them further. Thanks for any help/advice!

J

edit: no I don't want the count of the number of coords in each bin, I need the bin label (say i,j and running from 1,1 to 25,25) of each pair of coordinates x,y. Hope this makes sense... thanks!

[Doug Hull]

By Bin label, do you mean the count of the number of data points in each bin? Please edit your originial question to clarify.

Answer 1

[Sean de Wolski]

Yea, you'll be able to do this using histc() and accumarray():

x = ceil(rand(1000,1)*10);  %x
y = ceil(rand(1000,1)*10);  %y
z = rand(1000,1);           %values
edges = 1:10;  %some edges to bin along
[~, idxx] = histc(x,edges);  %Which x bin?
[~, idxy] = histc(y,edges);  %Which y bin?

averages = accumarray([idxx idxy],z,[],@mean);  %Build the average matrix