public static function PHPExcel_Calculation_Statistical::FORECAST in Loft Data Grids 7.2

Same name and namespace in other branches

1. 6.2 vendor/phpoffice/phpexcel/Classes/PHPExcel/Calculation/Statistical.php \PHPExcel_Calculation_Statistical::FORECAST()

* FORECAST * * Calculates, or predicts, a future value by using existing values. The predicted value is a y-value for a given x-value. * *

Parameters

float Value of X for which we want to find Y: * @param array of mixed Data Series Y * @param array of mixed Data Series X * @return float

File

vendor/phpoffice/phpexcel/Classes/PHPExcel/Calculation/Statistical.php, line 1556

Class

PHPExcel_Calculation_Statistical

PHPExcel_Calculation_Statistical

Code

public static function FORECAST($xValue, $yValues, $xValues) {
  $xValue = PHPExcel_Calculation_Functions::flattenSingleValue($xValue);
  if (!is_numeric($xValue)) {
    return PHPExcel_Calculation_Functions::VALUE();
  }
  if (!self::_checkTrendArrays($yValues, $xValues)) {
    return PHPExcel_Calculation_Functions::VALUE();
  }
  $yValueCount = count($yValues);
  $xValueCount = count($xValues);
  if ($yValueCount == 0 || $yValueCount != $xValueCount) {
    return PHPExcel_Calculation_Functions::NA();
  }
  elseif ($yValueCount == 1) {
    return PHPExcel_Calculation_Functions::DIV0();
  }
  $bestFitLinear = trendClass::calculate(trendClass::TREND_LINEAR, $yValues, $xValues);
  return $bestFitLinear
    ->getValueOfYForX($xValue);
}