The following Matlab project contains the source code and Matlab examples used for function to make a 2d histogram.
%A Simple function that makes a 2D histgram
% Input: data: two cols, x value; y value
% xrange: range and bins for x value (edges)
% yrange: range and bins for y value (edges)
%Output: Count of a specifice (x,y) bin combination;
% Suggested visualizing tool: I like to use imagesc; bar3 will work fine
% too; have to change axis label though