PHP - Stats Rand Gen Ipoisson() Function

---

---

Definition and Usage

The stats_rand_gen_ipoisson() function can generate a single random deviate from a Poisson distribution.

Syntax

  int stats_rand_gen_ipoisson( float $mu )

Parameters

Return Values

The stats_rand_gen_ipoisson() function can return a random deviate from the Poisson distribution with parameter mu.

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 random deviation from the Poisson distribution with parameter 1.

<?php
   var_dump(is_int(stats_rand_gen_ipoisson(1)));
?>

Output

This will produce following result −

bool(true)

Example

In the following example, we compute random deviate from the Poisson distribution with parameter 0.

<?php
   var_dump(stats_rand_gen_ipoisson(0));
?>

Output

This will produce following result −

int(0)

Example

Following is an error case. In the following example, we pass mu < 0. A warning is displayed in logs.

<?php
   // error cases
   var_dump(stats_rand_gen_ipoisson(-0.1));    // mu < 0
?>

Output

This will produce following result and a warning in logs PHP Warning: stats_rand_gen_ipoisson(): mu < 0.0 . mu : -1.000000E-1

bool(false)