When we did LSI on the database/regression example, we used the raw
(non-tf/idf) weights. What, if any, are the interactions between
tf/idf and LSI? Try to answer this by doing LSI on the tf/idf versio
of the d-t matrix for database/regression example. (You may use
MATLAB). Try to make a plot similar to the two dimensional plot we did
for LSI (that showed Database and SQL are similar).