Counts in each bin for 2d histogram ?

I have two vectors X and Y. To construct a 2D histogram, I have to create a grid on scatter plot of X,Y. And count number of data points in each small square of the grid that will be my frequency. Can someone help me how to decide number of bins and any matlab function to count the frequency in each small square ?

Answer 1

[Stephen23]

Have a look at these functions:

hist3

histcounts2 Introduced in 2015b

histcn on FEX

[dipak sanap]

Thanks for reply but my matlab version dose not have these fucntion. I have only, histc. Do you have any idea how to use this to construct 2D histogram ?

[Stephen23]

That is exactly why I gave you the link to histcn on FEX. It creates a 2D histogram with the outputs you want. That is why I gave you a link to it. Note that it is a third-party function, so you will need to download it and put in on your MATLAB path or in the current directory. The download button is in the top right corner, labelled "Download Zip".

[Brando Miranda]

do you know how to plot things with histcounts2?

[Steven Lord]

If you want to see a 2-dimensional histogram plot, use histogram2 instead of histcounts2. The interfaces of those two functions are very similar, but the intent of the histcounts2 function is to let you bin the data without plotting anything. In histogram2, the ouput is the graphics object.

[Image Analyst]

histogram2() gives an object with lots of info, if you choose to accept it:

x = randn(1000,1);
y = randn(1000,1);
h = histogram2(x,y)

h = 
  Histogram2 with properties:

               Data: [1000×2 double]
             Values: [13×13 double]
            NumBins: [13 13]
          XBinEdges: [-3.5 -3 -2.5 -2 -1.5 -1 -0.5 0 0.5 1 1.5 2 2.5 3]
          YBinEdges: [-3.5 -3 -2.5 -2 -1.5 -1 -0.5 0 0.5 1 1.5 2 2.5 3]
           BinWidth: [0.5 0.5]
      Normalization: 'count'
          FaceColor: 'auto'
          EdgeColor: [0.15 0.15 0.15]

plus more...