NAME

AI::FANN - Fast Artificial Neural Network library Perl wrapper

SYNOPSIS

Train...

use AI::FANN qw(:all);

# create an ANN with 2 inputs, a hidden layer with 3 neurons and an
# output layer with 1 neuron:
my $ann = AI::FANN->new_standard(2, 3, 1);

$ann->hidden_activation_function(FANN_SIGMOID_SYMMETRIC);
$ann->output_activation_function(FANN_SIGMOID_SYMMETRIC);

# create the training data for a XOR operator:
my $xor_train = AI::FANN::TrainData->new( [-1, -1], [-1],
                                          [-1, 1], [1],
                                          [1, -1], [1],
                                          [1, 1], [-1] );

$ann->train_on_data($xor_train, 500000, 1000, 0.001);

$ann->save("xor.ann");

Run...

use AI::FANN;

my $ann = AI::FANN->new_from_file("xor.ann");

for my $a (-1, 1) {
  for my $b (-1, 1) {
    my $out = $ann->run([$a, $b]);
    printf "xor(%f, %f) = %f\n", $a, $b, $out->[0];
  }
}

DESCRIPTION

WARNING:  THIS IS A VERY EARLY RELEASE,
          SERIOUS BUGS ARE EXPECTED!!!

AI::FANN is a Perl wrapper for the Fast Artificial Neural Network (FANN) Library available from http://fann.sourceforge.net.

An object oriented interface provides a direct map to the C functions but with some changes to make it more perlish:

  • Two classes are used: AI::FANN that wraps the C struct fann type and AI::FANN::TrainData that wraps struct fann_train_data.

  • Prefixes and common parts on the C function names referring to those structures have been removed. For instance C fann_train_data_shuffle becomes AI::FANN::TrainData::shuffle.

  • Pairs of C get/set functions are wrapped in Perl with dual accessor methods. For instance:

    $ann->bit_fail_limit($limit); # sets the bit_fail_limit
    
    $bfl = $ann->bit_fail_limit;  # gets the bit_fail_limit

    Indexed pairs of get/set functors are also wrapped inside dual accessors:

    # sets:
    $ann->neuron_activation_function($layer, $neuron, $actfunc);
    
    # gets:
    $af = $ann->neuron_activation_function($layer, $neuron);

    Note that on the Perl version, the optional value argument is moved to the last position (on the C version it is usually the second argument).

    Some functions have been renamed to make the naming more consistent:

    C                                      Perl
    -----------------------------------------------------------
    fann_create_from_file               => new_from_file
    fann_create_standard                => new_standard
    fann_get_num_input                  => num_inputs
    fann_get_activation_function        => neuron_activation_function
    fann_set_activation_function        => ^^^
    fann_set_activation_function_layer  => layer_activation_function
    fann_set_activation_function_hidden => hidden_activation_function
    fann_set_activation_function_output => output_activation_function
  • Boolean methods return true on success and undef on failure.

  • Any error reported from the C side is converter to a Perl exception.

  • Memory management is automatic, no need to call destroy methods.

  • Doubles are used for computations.

CONSTANTS

All the constants defined in the C documentation are exported from the module:

# import all...
use AI::FANN ':all';

# or individual constants...
use AI::FANN qw(FANN_TRAIN_INCREMENTAL FANN_GAUSSIAN);

The values returned from this constant subs yield the integer value on numerical context and the constant name when used as strings.

CLASSES

The classes defined by this package are:

AI::FANN

Wraps C struct fann types and provides the following methods:

FANN::AI->new_standard(@layer_sizes)

-

FANN::AI->new_sparse($connection_rate, @layer_sizes)

-

FANN::AI->new_shortcut(@layer_sizes)

-

FANN::AI->new_from_file($filename)

-

$ann->save($filename)

-

$ann->run($input)

input is an array with the input values.

returns an array with the values on the output layer.

$out = $ann->run([1, 0.6]);
print "@$out\n";
$ann->randomize_weights($min_weight, $max_weight)
$ann->train($input, $desired_output)

$input and $desired_output are arrays.

$ann->test($input, $desired_output)

$input and $desired_output are arrays.

It returns an array with the values of the output layer.

$ann->reset_MSE

-

$ann->train_on_file($filename, $max_epochs, $epochs_between_reports, $desired_error)

-

$ann->train_on_data($train_data, $max_epochs, $epochs_between_reports, $desired_error)

$train_data is a AI::FANN::TrainData object.

$ann->cascadetrain_on_file($filename, $max_neurons, $neurons_between_reports, $desired_error)

-

$ann->cascadetrain_on_data($train_data, $max_neurons, $neurons_between_reports, $desired_error)

$train_data is a AI::FANN::TrainData object.

$ann->train_epoch($train_data)

$train_data is a AI::FANN::TrainData object.

$ann->print_connections

-

$ann->print_parameters

-

$ann->cascade_activation_functions()

returns a list of the activation functions used for cascade training.

$ann->cascade_activation_functions(@activation_functions)

sets the list of activation function to use for cascade training.

$ann->cascade_activation_steepnesses()

returns a list of the activation steepnesses used for cascade training.

$ann->cascade_activation_steepnesses(@activation_steepnesses)

sets the list of activation steepnesses to use for cascade training.

$ann->training_algorithm
$ann->training_algorithm($training_algorithm)

-

$ann->train_error_function
$ann->train_error_function($error_function)

-

$ann->train_stop_function
$ann->train_stop_function($stop_function)

-

$ann->learning_rate
$ann->learning_rate($rate)

-

$ann->learning_momentum
$ann->learning_momentum($momentun)

-

$ann->bit_fail_limit
$ann->bit_fail_limit($bfl)

-

$ann->quickprop_decay
$ann->quickprop_decay($qpd)

-

$ann->quickprop_mu
$ann->quickprop_mu($qpmu)

-

$ann->rprop_increase_factor
$ann->rprop_increase_factor($factor)

-

$ann->rprop_decrease_factor
$ann->rprop_decrease_factor($factor)

-

$ann->rprop_delta_min
$ann->rprop_delta_min($min)

-

$ann->rprop_delta_max
$ann->rprop_delta_max($max)

-

$ann->num_inputs

-

$ann->num_outputs

-

$ann->total_neurons

-

$ann->total_connections

-

$ann->MSE

-

$ann->bit_fail

-

cascade_output_change_fraction
cascade_output_change_fraction($fraction)

-

$ann->cascade_output_stagnation_epochs
$ann->cascade_output_stagnation_epochs($epochs)

-

$ann->cascade_candidate_change_fraction
$ann->cascade_candidate_change_fraction($fraction)

-

$ann->cascade_candidate_stagnation_epochs
$ann->cascade_candidate_stagnation_epochs($epochs)

-

$ann->cascade_weight_multiplier
$ann->cascade_weight_multiplier($multiplier)

-

$ann->cascade_candidate_limit
$ann->cascade_candidate_limit($limit)

-

$ann->cascade_max_out_epochs
$ann->cascade_max_out_epochs($epochs)

-

$ann->cascade_max_cand_epochs
$ann->cascade_max_cand_epochs($epochs)

-

$ann->cascade_num_candidates

-

$ann->cascade_num_candidate_groups
$ann->cascade_num_candidate_groups($groups)

-

$ann->neuron_activation_function($layer_index, $neuron_index)
$ann->neuron_activation_function($layer_index, $neuron_index, $activation_function)

-

$ann->layer_activation_function($layer_index, $activation_function)

-

$ann->hidden_activation_function($layer_index, $activation_function)

-

$ann->output_activation_function($layer_index, $activation_function)

-

$ann->neuron_activation_steepness($layer_index, $neuron_index)
$ann->neuron_activation_steepness($layer_index, $neuron_index, $activation_steepness)

-

$ann->layer_activation_steepness($layer_index, $activation_steepness)

-

$ann->hidden_activation_steepness($layer_index, $activation_steepness)

-

$ann->output_activation_steepness($layer_index, $activation_steepness)

-

$ann->num_layers

returns the number of layers on the ANN

$ann->layer_num_neurons($layer_index)

return the number of neurons on layer $layer_index.

$ann->num_neurons

return a list with the number of neurons on every layer

AI::FANN::TrainData

Wraps C struct fann_train_data and provides the following method:

AI::FANN::TrainData->new_from_file($filename)
AI::FANN::TrainData->new($input1, $output1 [, $input2, $output2, ...])

$inputx and $outputx are arrays with the values of the input and output layers.

AI::FANN::TrainData->new_empty($num_data, $num_inputs, $num_outputs)

returns a new AI::FANN::TrainData object of the sizes indicated on the arguments. The values of the data contained inside the object are random and should be set before using it for training a ANN.

$train->data($index)

returns two arrays with the values of the input and output layer respectively for that index.

$train->data($index, $input, $output)

$input and $output are two arrays.

The input and output layers at the index $index are set to the values on these arrays.

$train->shuffle

-

$train->scale_input($new_min, $new_max)

-

$train->scale_output($new_min, $new_max)

-

$train->scale($new_min, $new_max)

-

$train->subset($pos, $length)

-

$train->num_inputs

-

$train->num_outputs

-

$train->length

-

SEE ALSO

FANN homepage at http://leenissen.dk/fann/index.php.

BUGS

Send bug reports to my email address or use the CPAN RT system.

COPYRIGHT AND LICENSE

Copyright (C) 2006 by Salvador Fandiño (sfandino@yahoo.com).

This Perl module is free software; you can redistribute it and/or modify it under the same terms as Perl itself, either Perl version 5.8.8 or, at your option, any later version of Perl 5 you may have available.

The Fast Artificial Neural Network Library (FANN) Copyright (C) 2003-2006 Steffen Nissen (lukesky@diku.dk) and others.

Distributed under the GNU Lesser General Public License.