# JointDist

## PURPOSE

JOINTDIST

## SYNOPSIS

function [P bins] = JointDist(x,y,nbins)

## DESCRIPTION

    JOINTDIST
       Usage: [P bins] = JointDist(x,y,nbins)

    This function calculates the joint distribution of the variables x and y.
    It is simply a normalized histogram using hist3. nbins can take any form
    of bins that hist3 can take, but no other hist3 options.

## CROSS-REFERENCE INFORMATION

This function calls:

This function is called by:

## SOURCE CODE

    0001 function [P bins] = JointDist(x,y,nbins)
    0002
    0003 %JOINTDIST
    0004 %   Usage: [P bins] = JointDist(x,y,nbins)
    0005 %
    0006 %This function calculates the joint distribution of the variables x and y.
    0007 %It is simply a normalized histogram using hist3. nbins can take any form
    0008 %of bins that hist3 can take, but no other hist3 options.
    0009
    0010 %Written by Dan Valente
    0011 %October 2007
    0012
    0013 %ensure x and y are both column matrices
    0014 [nrowsx,ncolsx] = size(x);
    0015 if (ncolsx ~= 1)
    0016     x = x';
    0017 end
    0018 [nrowsy,ncolsy] = size(y);
    0019 if (ncolsy ~= 1)
    0020     y = y';
    0021 end
    0022
    0023
    0024 [H bins] = hist3([x y], nbins);
    0025 N = sum(sum(H));
    0026 binsize_x = bins{1}(3)-bins{1}(2);
    0027 binsize_y = bins{2}(3)-bins{2}(2);
    0028 P = H./(N*binsize_x*binsize_y);  %Normalize correctly
    0029
    0030
    0031 return;
    0032