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inpho / vsm

Vector Space Model Framework developed for InPhO
http://inpho.github.io/vsm
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Use arccos to calculate dissimilarity #60

Closed junotk closed 11 years ago

junotk commented 11 years ago

An S675 student pointed me out that to convert cosine similarity to dissimilarity one must use arccos(x), rather than 1-x. We are using dissimilarity matrices in isomap, so they need to be fixed.

http://inpho.cogs.indiana.edu/datablog/the-shape-of-philosophy-pt-1/#comment-265

junotk commented 11 years ago

Fixed in develop branch. But cluster algorithms use metric, and seemingly convert similarity to dissimilarity --- very possibly with 1-x. That must be checked as well.

junotk commented 11 years ago

We will use Jansen-Shannon divergence for the cluster algorithms, so there will be no problem.