Vectorized Implementation of Softmax Regression

Question

I’m implementing softmax regression in Octave. Currently I’m using a non-vectorized implementation using following cost function and derivatives.

Source: Softmax Regression

Now I want to implement vectorized version of it in Octave. It seems like bit hard for me to write vectorized versions for these equations. Can somebody help me to implement this ?

Thanks

Upul

Answer 1

This is very similar to an exercise in Andrew Ng's deep learning class, they give some hints http://ufldl.stanford.edu/wiki/index.php/Exercise:Vectorization