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EM Algorithm Applet [3 P]

Go to Olivier Michel's applet Gaussian Mixture Model EM Algorithm at http://diwww.epfl.ch/mantra/tutorial/english/gaussian/html/ and answer questions 1-6. Additionally do the following:
a)
Create points from two intersecting lines and run the algorithm with option LineMix and 2 clusters. Click repeatedly on EM 1 Step to run the algorithm. Repeat this experiment with different cutting angles of the lines and analyze if this has an effect on the number of iterations until convergence.
b)
Create points in a ring around the center with the button RingPts. Try to fit a mixture of lines model (with EM Run) to this distribution and analyze what happens when you change the number of lines. Do the same experiment with mixtures of Gaussians and describe what you find.



Pfeiffer Michael 2006-01-18