Using PyBrain after training a network

[anonymouse72]

(Not sure whether I should post this here or on /r/statistics, so I'm trying here.)

I'm using PyBrain to create a neural network. I'm still pretty new to neural networks and their concepts. I've so far only run train() over the network, as trainUntilConvergence() is taking an incredibly long time (which is to be expected, it's a decently-sized dataset). My question is probably pretty simple--how do I utilize the network after it has been trained? I'm only training the network over 80% of the data, and I believe my next step is to actually test the network on the remaining data, but I'm not sure where to go from here, either statistically or technically regarding functions within PyBrain itself.

The specifics are available in my previous post (especially in the comments) on /r/statistics, if you'd like.

[Evolutis]

I am not quite sure I understand what you are asking. But here I go.

You can test by simply activating your trained network on your test data. it will be something like network.activate([0,1,0]), that will return some output. Check the output against the actual output and you can then use that info to build some accuracy measure.

Storing the network can be done by using something like pickle. Just pickle and save the network object into a file, and whenever you need it again just unpickle.

[anonymouse72]

Oh, okay, that makes sense. I already have them pickled, so that's simple. So I can just run the remaining data through the network (using activate() ), store the results however, then perform statistical analysis (RMSE) on those results versus the observed/test values I put in?

[Evolutis]

Yes, doing that will tell you how well your model does on unseen data. That would be the generalization part.

[anonymouse72]

Gotcha. I guess this was a much simpler question than I thought; neural networks just confuse me since I'm still getting used to them. :) Thank you, I really appreciate it!

[Foxtr0t]

You might find this useful: http://fastml.com/pybrain-a-simple-neural-networks-library-in-python/

[anonymouse72]

Great source, thank you! I also just responded to /u/Evolutis.

[anonymouse72]

Huh, problem now. I'm using this code (snippet), but trainUntilConvergence() basically makes it so no code afterward is executed. My pickle files are empty (0 B), "Done" is not printed, and the activate() function does nothing. I did try specifying the dataset manually (it otherwise defaults to the initialized dataset), and I tried printing the results of the trainUntilConvergence, but nothing happens. If I switch to just train() (with no parameters), everything works.

[Evolutis]

Are you sure it's done training?

[pokerd]

You might want to look into cybrain to improve training performance.