sigmoid activation function. This code is imported into the NNFlex namespace during init

syntax:

        my $value = $network->tanh(<value>);

You also need the 'slope' (i.e. you need to integrate the activation function) and supply that as <function>_slope. See below if you are writing your own activation functions.

Copyright (c) 2004-2005 Charles Colbourn. All rights reserved. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.