php-ai / php-ml

    protected function runTraining()

    {

        // The cost function is the sum of squares

        $callback = function ($weights, $sample, $target) {

            $this->weights = $weights;

            $output = $this->output($sample);

            $gradient = $output - $target;

            $error = $gradient ** 2;

            return [$error, $gradient];

        };

        $isBatch = $this->trainingType == self::BATCH_TRAINING;

     * Trains the perceptron model with Stochastic Gradient Descent optimization

     * to get the correct set of weights

     */

    protected function runTraining()

    {

        // The cost function is the sum of squares

        $callback = function ($weights, $sample, $target) {

            $this->weights = $weights;

            $prediction = $this->outputClass($sample);

            $gradient = $prediction - $target;

            $error = $gradient**2;

            return [$error, $gradient];

        };

        $this->runGradientDescent($callback);

    }

    /**

     * Executes Stochastic Gradient Descent algorithm for