Using nntool for number recognition

Hi,

I read many documents regarding neural networks and nntool Toolbox for MATLAB+ demos ..etc. However, I still can't understand how to use the nntool! Most what available in the net and documentations are based on either small data set or template data sets. No one illustrates a real recognition example for a number or a letter using nntool.

I need to use nntool to build a neural network, train the data and then do a test with a new data. For example, I have two leters as two images (letter A and letter B). I need to train the system on these images and do a test from different images that also represent letter A and letter B.

Now, I could manage to read an image (data set: 11 x 11 pixels), I could also convert it to binray representation. I could import it as new data using nntool. I could create new network with required parameters like number of neurons , step function type , back-propagation ...etc. But I don't know what the output should be, how to train the data, what is the value as the target, what the input should look like? is the input has to be two inputs as for Letter A and letter B? do I need to train the network for each letter one by one or what? does the input has to be one row or one column or leave it as it is bieng a matrix of n x m? I understand the concept of AI and Neural Network, perceptron and neuron, but I dont know how to use nntool to apply the concept.

I really appreciate if there is a single small example for recognising a letter or a number using nntool. Note: it is recognition but not detection and I'm using MATLAB R2010B.

Best Regards Nayef

Answer 1

[Walter Roberson]

Odd, that's not what posters have said in the past; they have referenced specific letter recognition demonstrations. See for example this discussion written by Greg Heath: http://www.mathworks.com/matlabcentral/newsreader/view_thread/290771

[Nayef]

Thank you for the reply. The provided link includes a link which at the moment not working any more!

Regards

Nayef

[Walter Roberson]

Hmmmm, possibly the apprc1 example of chapter 11 of the manual no longer exists in current versions.

See

http://www.mathworks.com/matlabcentral/fileexchange/8676

[Nayef]

Thank you very much, I could locate apprc1 in the manual of NN, it is a really helpfull example, clear and can be applied at simple level.

Thanx again.