# How can I display empirical pdf of my 100x1 vector data in Matlab?

I have a data which is 100x1 vector. How can I display its empirical pdf in Matlab? Also, if I want to compare the pdf of three vectors on the same graph, then how to do that?

Right now I am using pdfplot.m file to plot my empirical pdf, however when I want to compare the 3 distributions by using 'hold on', then firstly its not working and secondly all the distributions are in same color. Thanks!

Also, I don't want to plot cdf or histogram.

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## 2 Answers

the problem is that histc plots bars instead of, say lines; the bars are plotted over one another. you should edit pdfplot to plot lines instead. look for the hist command and alter it.

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 Thanks! It is solved now, though with hist only. – Pupil Sep 29 '10 at 22:14

I would suggest using the ksdensity function. In the following example I compare the pdf of the data in column 1 of matrix 1 with the pdf of the data in column 2 of matrix 2:

[f,x] = ksdensity(mat1(:,1));
plot(x,f,'--b');hold
[f,x] = ksdensity(mat2(:,2));
plot(x,f,'--m')
legend('Data 1 pdf', 'Data 2 pdf');

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