PHP FANN wrapper

This is a PHP wrapper for FANN (Fast Artificial Neural Network) library.

API

The API is documented on http://www.php.net/manual/en/book.fann.php where is the complete documentation for PHP FANN.

The API is very similar to the official FANN C API. Just functions for fixed fann_type have not been mapped because PHP always support float. In addition unnecessary arguments for some functions have been left out (for example array length that is not necessary for PHP arrays).

Installation

The extension can be installed on Linux and Windows.

Linux

Before you start installation make sure that libfann is installed on your system. It's part of the main repository in the most Linux distributions (search for fann). If not you need to install it first. Either download it from the official site or get it from your distro repository. For example on Ubuntu:

$ sudo apt-get install libfann-dev

Fann installation can be skipped if an RPM for Fedora is used (libfann is in the package dependencies).

Fedora

The RPM package for PHP FANN is available in Remi's repository: http://rpms.famillecollet.com/

It is available only for Fedora. RHEL and clones (CentOS, SC and others) are not available as libfann is not available in EPEL.

After downloading remi-release RPM, the package can be installed by executing following command:

$ sudo yum --enablerepo=remi install php-pecl-fann

PECL

This extension is available on PECL. The installation is very simple. Just run:

$ sudo pecl install fann

Manual Installation

First download the source

git clone https://github.com/bukka/php-fann.git

Then go to the created source directory and compile the extension. You need to have a php development package installed (command phpize must be available).

cd php-fann
phpize
./configure --with-fann
make
sudo make install

Finally you need to add

extension=fann.so

to the php.ini

Windows

Precompiled binary dll libraries for php-fann and libfann are available on the official Windows download site for PECL packages. The compiled version of libfann is 2.2.

Examples

These are just two basic examples for simple training and running supplied data on the trained network.

simple_train.php

$num_input = 2;
$num_output = 1;
$num_layers = 3;
$num_neurons_hidden = 3;
$desired_error = 0.001;
$max_epochs = 500000;
$epochs_between_reports = 1000;

$ann = fann_create_standard($num_layers, $num_input, $num_neurons_hidden, $num_output);

if ($ann) {
    fann_set_activation_function_hidden($ann, FANN_SIGMOID_SYMMETRIC);
    fann_set_activation_function_output($ann, FANN_SIGMOID_SYMMETRIC);

    $filename = dirname(__FILE__) . "/xor.data";
    if (fann_train_on_file($ann, $filename, $max_epochs, $epochs_between_reports, $desired_error))
        fann_save($ann, dirname(__FILE__) . "/xor_float.net");

    fann_destroy($ann);
}

simple_test.php

$train_file = (dirname(__FILE__) . "/xor_float.net");
if (!is_file($train_file))
    die("The file xor_float.net has not been created! Please run simple_train.php to generate it");

$ann = fann_create_from_file($train_file);
if (!$ann)
	die("ANN could not be created");

$input = array(-1, 1);
$calc_out = fann_run($ann, $input);
printf("xor test (%f,%f) -> %f\n", $input[0], $input[1], $calc_out[0]);
fann_destroy($ann);