PHP - Stats Rand Gen Ibinomial() Function

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Definition and Usage

The stats_rand_gen_ibinomial() function generates a single random deviate from a binomial distribution whose number of trials is "n" (n >= 0) and whose probability of an event in each trial is "pp" ([0;1]).

Syntax

  int stats_rand_gen_ibinomial( int $n, float $pp )

Parameters

Return Values

The stats_rand_gen_ibinomial() function can return a random deviate from the binomial distribution whose number of trials is n, and whose probability of an event in each trial is pp.

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 deviatition from the binomial distribution whose number of trials is 0, and whose probability of an event in each trial is 0.7.

<?php
   var_dump(stats_rand_ibinomial(0, 0.7));
?>

Output

This will produce following result −

int(0)

Example

In the following example, we compute random deviatition from the binomial distribution whose number of trials is 3, and whose probability of an event in each trial is 0.

<?php
   var_dump(stats_rand_ibinomial(3, 0));
?>

Output

This will produce following result −

int(0)

Example

In the following example, we compute random deviatition from the binomial distribution whose number of trials is 3, and whose probability of an event in each trial is 1.

<?php
   var_dump(stats_rand_ibinomial(3, 1));
?>

Output

This will produce following result −

int(3)

Example

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

<?php
   // error cases
   var_dump(stats_rand_ibinomial(-1, 0.7));    // n < 0
?>

This will produce following result and a warning in logs PHP Warning: stats_rand_ibinomial(): Bad values for the arguments. n : -1 pp : 7.000000E-1vs

bool(false)

Example

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

<?php
   // error cases
   var_dump(stats_rand_ibinomial(3, -0.1));    // pp < 0
?>

Output

This will produce following result and a warning in logs PHP Warning: stats_rand_ibinomial(): Bad values for the arguments. n : 3 pp : -1.000000E-1

bool(false)

Example

Following is an error case. In the following example, we pass pp > 1. A warning is displayed in logs.

<?php
   // error cases
   var_dump(stats_rand_ibinomial(3, 1.1));     // pp > 1
?>

Output

This will produce following result and a warning in logs PHP Warning: stats_rand_ibinomial(): Bad values for the arguments. n : 3 pp : 1.100000E+0

bool(false)