About ploting values in array and holding them

I have following code as function

function PlotSample(x)
  figure(1);
  sublot(3,1,1);
  [a,b]=hist(x);
  hold on;
  a=100*(a./size(x,1));
end

Now if i have diffrent values of x like x1,x2 and x3 all having size 100*2 then how to plot 6 histograms in 1 plot?

Answer 1

[Walter Roberson]

http://www.mathworks.com/help/matlab/ref/histogram.html#buiynvy-13 together with http://www.mathworks.com/help/matlab/ref/histogram.html#namevaluepairs 'Normalization', 'probability'