re: "Thoughts on Understanding Neural Networks"

Great post by Gordon Linoff the the Data Miners.com Blog about visualising Neural Networks

http://www.data-miners.com/blog/2009/01/thoughts-on-understanding-neural.html

I usually get better predictive success using neural nets, but the lack of explain-ability is always a downside. I'm always keen to see ways that might help explain or interpret a Neural Network. A few years ago I tried a simple graphical way to show a Neural Net, but I think Gordon's recent post highlights better options.

My example is written in VB.NET and parses a single hidden layer Neural Network saved as PMML into data grids. Once the neural net neurons and weights are loaded into the data grids I then read from the data grids and create a graphic of the Neural Net. Transparency is used to show the strength of the weight, whilst colour (blue or red) is used to show the negative or positive effect) . You can view my example at;

http://www.kdkeys.net/forums/thread/6495.aspx
and download the source code, executable and example PMML directly from here;

http://www.kdkeys.net/forums/6495/PostAttachment.aspx

I can't post images as comments on Gordon's blog so below are two snapshots of the simple UI application that displays the Neural Net PMML graphic.

a) graphic




b) PMML loaded into data grids



Cheers

- Tim