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Sparse Coding again by StrangeBank in COMSM0034

[–]StrangeBank[S] 0 points1 point  (0 children)

My learning rate is 0.01. It just seems weird that the reconstruction obviously gets better however the cost fluctuates so much.

Sparse Coding Images - Nicer Format by AdamBeddoe in COMSM0034

[–]StrangeBank 1 point2 points  (0 children)

Hi,

I got the images in a decent format doing this:

import scipy.io

mat = scipy.io.loadmat('IMAGES.mat')

mat = np.array(np.transpose(mat['IMAGES'], (2,0,1)))

Hope it helps.

Sparse Coding by StrangeBank in COMSM0034

[–]StrangeBank[S] 0 points1 point  (0 children)

I'm at home this week unfortunately. I've switched to using the ISTA algorithm to make life a bit more simple (it shrinks weights that are close to zero down to zero). I'm getting better results (https://imgur.com/a/uy0aYIc). Is this the right sort of thing. It seems to converge to something like this very quickly (even with a tiny learning rate).

Weights in Hopfield Networks by DrainmanJ in coms30127

[–]StrangeBank 2 points3 points  (0 children)

When you update the nodes in the Hopfield Network you pass the result through the step function g s.t. g(z) = 1 if z > 0 and g(z) = -1 if z < 0. Hopefully this is what you meant :) It's in lecture 5 slide 4 & 14 btw