June 19, 2006
playing with GMMs
I'm starting to look at the GMMs more closely to figure out what's going on with hubs. One thing I wondered was how well-spread the mixture components are; are they all on top of each other, are there are few outliers that might be dominating, or what?
here's a plot of a GMM for one song (wham/freedom). the top is the euclidean distance kernel between mixture centers, and the middle is the trace (sum of evalues) of the covariance matrices, and the bottom is the determinant (prod of evalues). The determinant is what we ought to be interested in, it's generally thought of as the size of the matrix. but curiously, the outlier shows up as a peak in the trace. i'll have to think about that.
[thought about it for a minute and realized that they're closely related by a log, but i'm not sure if there should be any major difference.]
Next step would be to look at which mfcc frames activate which components, and what happens with these outliers. silence? or are they catch-all components?
Posted by madadam at June 19, 2006 01:15 PM