PHP - Stats Dens Weibull() Function

Definition and Usage

The stats_dens_weibull() function is a probability density function of the Weibull distribution.

Syntax

  float stats_dens_weibull( float $x, float $a, float $b )

Parameters

Return Values

The stats_dens_weibull() function can return the probability density at x, where the random variable can follow the Weibull distribution in which the shape parameter is a, and the scale parameter is b, or return false on failure.

Dependencies

This function was first introduced in statistics extension (PHP 4.0.0 and PEAR 1.4.0). We have used latest release of stats-2.0.3 (PHP 7.0.0 or newer and PEAR 1.4.0 or newer) for this tutorial

Example

In the following example, we compute probability density at each x.

<?php
   // check for each x
   foreach (range(0, 2, 0.5) as $x) {
      var_dump(round(stats_dens_weibull($x, 2, 3), 6));
      echo "<br>";
   }
?>

Output

This will produce following result −

  float(0)
  float(0.108067)
  float(0.198853)
  float(0.2596)
  float(0.284969)

Example

In the following example, we compute probability density for each a.

<?php
   // check for each a
   foreach (range(0.5, 2, 0.5) as $a) {
      var_dump(round(stats_dens_weibull(1, $a, 3), 6));
      echo "<br>";
   }
?>

Output

This will produce following result −

  float(0.162058)
  float(0.238844)
  float(0.238138)
  float(0.198853)

Example

In the following example, we compute probability density for each b.

<?php
   // check for each b
   foreach (range(0.5, 2, 0.5) as $b) {
      var_dump(round(stats_dens_weibull(1, 2, $b), 6));
      echo "<br>";
   }
?>

Output

This will produce following result −

  float(0.146525)
  float(0.735759)
  float(0.569938)
  float(0.3894)