php-ai / php-ml

            // the average value for the cut point

            $threshold = array_sum($values) / (float) count($values);

            $errorRate = $this->calculateErrorRate($threshold, $operator, $values);

            if ($split == null || $errorRate < $split['trainingErrorRate']) {

                $split = ['value' => $threshold, 'operator' => $operator,

                        'column' => $col, 'trainingErrorRate' => $errorRate];

            }

            // Try other possible points one by one

            for ($step = $minValue; $step <= $maxValue; $step+= $stepSize) {

            for ($step = $minValue; $step <= $maxValue; $step+= $stepSize) {

                $threshold = (float)$step;

                $errorRate = $this->calculateErrorRate($threshold, $operator, $values);

                if ($errorRate < $split['trainingErrorRate']) {

                    $split = ['value' => $threshold, 'operator' => $operator,

                        'column' => $col, 'trainingErrorRate' => $errorRate];

                }

            }// for

        }

            foreach ($distinctVals as $val) {

                $errorRate = $this->calculateErrorRate($val, $operator, $values);

                if ($split == null || $split['trainingErrorRate'] < $errorRate) {

                    $split = ['value' => $val, 'operator' => $operator,

                        'column' => $col, 'trainingErrorRate' => $errorRate];

                }

            }// for

        }