Practical PCA tutorial with data

Question

Searching the internet for PCA tutorial gives thousands of results (even videos). Many of the tutorials are very good. But I am not able to find any practical example where PCA is explained using some data-sets which I can use for demonstration. I need a tutorial which provides some small data set which is easy to plot (not 10000s of lines of data with 100s of dimension) before and after the PCA analysis and the difference/results can be clearly demonstrated. (I think a step-by-step practical example with a data having about some 100 lines and 3 dimension will be great).

Do you have any suggestion??

Answer 1

Simon Jackman has a nice tutorial example (PDF) of PCA in action using the case of image reconstruction. He uses the famous picture of Nixon meeting Elvis. It's fun and also serves to motivate the idea of dimensional reduction visually. The code he used is shown in the PDF file.

Answer 2

If you are familiar with R, this http://yatani.jp/HCIstats/PCA may be helpful as a basic tutorial. Only thing is that you need to do the plot yourself. The tutorial does not show the plots.

Answer 3

friend of mine gave a talk on it a couple of weeks ago, slides (with small data) and R code here: http://www.bimcore.emory.edu/bbseries/