Plotting multiple histograms on same plot

Hi there. My problem is this I have a directory which has 3000 'dna.out' files. And this is how Im loading them all in matlab :

files = dir('*.out');
for i = 1 : length(files)
  eval(['load ' files(i).name ]);
  hist(files(i).name, 300); 
  hold on;
end

But I need to plot all these 3000 files in a single figure.How can I use the undermentioned code in a loop to plot all the loaded files.

[n,r]=hist(dna23,300);
plot(r,n,'r-');grid on;
hold on

Im currently doing it manually and i have 5 more folders having thousands of files. Please help

Answer 1

[rob]

http://www.mathworks.com/matlabcentral/fileexchange/27316-histnorm

[Vinita]

thanx rob, but how do i generate dataset from a directory which could be fed into histnorm.

Answer 2

[Image Analyst]

Have you seen the FAQ: http://matlab.wikia.com/wiki/FAQ#How_can_I_process_a_sequence_of_files.3F

You don't want to do a histogram of your filename (a character array). You want a histogram of the contents of the filename, right?

Don't use eval. Do it this way:

for k = 1 : length(files)
  baseFileName = files(k).name;
  if exist(baseFileName , 'file')
    storedVariables = load(baseFileName);
    dna23= storedVariables.dna23;
    [counts binValues] = hist(dna23(:), 300);
    if k == 1
      allCounts = counts;
    else
      allCounts = allCounts + counts;
    end
  end
end
bar(allCounts);

Of course, don't forget to check that counts is the same size every time, to use fullfile(), try/catch, comments, and all the other things that go into making a robust and maintainable program.