Neutral Networks — Unrolling Parameters

With neural networks, we are working with sets of matrices:

In order to use optimizing functions such as “fminunc()”, we will want to “unroll” all the elements and put them into one long vector:

If the dimensions of Theta1 is 10x11, Theta2 is 10x11 and Theta3 is 1x11, above code will display a 231x1and

then we can get back our original matrices from the “unrolled” versions as follows:

Disclaimer — This series is based on the notes that I created for myself based on various books and videos I’ve read or seen , so some of the text could be an exact quote from some book/videos out there.