protected function getCodeFrequencyJson() { $frequencyInfo = $this->getModel()->getCodeFrequency(); $axis['xAxis'] = array_keys($frequencyInfo); $axis['yAxis'] = array('title' => 'Problem Count'); $series = array('Frequency' => array_values($frequencyInfo)); $config = array('title' => self::CODE_FREQUENCY_PLOT); return $this->chartHelper->getLineChartJson($config, $series, $axis); }