Saturday, December 21, 2013

Feature Hashing

Several months back, I was mentioning to Alex Smola about the high memory requirements when dealing with learning number of parameters - especially multiclass classification when the dimensions and number of classes are large. He suggested using Feature hashing as a technique to reduce the number of dimensions - thereby reducing the number of parameters to be learnt. I finally got around to testing how effective feature hashing really is.

TLDR: I tried feature hashing - it works but mostly at the cost of accuracy.