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Differences Between: [Versions 400 and 401]

   1  <?php
   2  
   3  namespace PhpOffice\PhpSpreadsheet\Calculation\Statistical\Distributions;
   4  
   5  use PhpOffice\PhpSpreadsheet\Calculation\ArrayEnabled;
   6  use PhpOffice\PhpSpreadsheet\Calculation\Exception;
   7  use PhpOffice\PhpSpreadsheet\Calculation\Information\ExcelError;
   8  
   9  class F
  10  {
  11      use ArrayEnabled;
  12  
  13      /**
  14       * F.DIST.
  15       *
  16       *    Returns the F probability distribution.
  17       *    You can use this function to determine whether two data sets have different degrees of diversity.
  18       *    For example, you can examine the test scores of men and women entering high school, and determine
  19       *        if the variability in the females is different from that found in the males.
  20       *
  21       * @param mixed $value Float value for which we want the probability
  22       *                      Or can be an array of values
  23       * @param mixed $u The numerator degrees of freedom as an integer
  24       *                      Or can be an array of values
  25       * @param mixed $v The denominator degrees of freedom as an integer
  26       *                      Or can be an array of values
  27       * @param mixed $cumulative Boolean value indicating if we want the cdf (true) or the pdf (false)
  28       *                      Or can be an array of values
  29       *
  30       * @return array|float|string
  31       *         If an array of numbers is passed as an argument, then the returned result will also be an array
  32       *            with the same dimensions
  33       */
  34      public static function distribution($value, $u, $v, $cumulative)
  35      {
  36          if (is_array($value) || is_array($u) || is_array($v) || is_array($cumulative)) {
  37              return self::evaluateArrayArguments([self::class, __FUNCTION__], $value, $u, $v, $cumulative);
  38          }
  39  
  40          try {
  41              $value = DistributionValidations::validateFloat($value);
  42              $u = DistributionValidations::validateInt($u);
  43              $v = DistributionValidations::validateInt($v);
  44              $cumulative = DistributionValidations::validateBool($cumulative);
  45          } catch (Exception $e) {
  46              return $e->getMessage();
  47          }
  48  
  49          if ($value < 0 || $u < 1 || $v < 1) {
  50              return ExcelError::NAN();
  51          }
  52  
  53          if ($cumulative) {
  54              $adjustedValue = ($u * $value) / ($u * $value + $v);
  55  
  56              return Beta::incompleteBeta($adjustedValue, $u / 2, $v / 2);
  57          }
  58  
  59          return (Gamma::gammaValue(($v + $u) / 2) /
  60                  (Gamma::gammaValue($u / 2) * Gamma::gammaValue($v / 2))) *
  61              (($u / $v) ** ($u / 2)) *
  62              (($value ** (($u - 2) / 2)) / ((1 + ($u / $v) * $value) ** (($u + $v) / 2)));
  63      }
  64  }