PHP | stats_rand_gen_ibinomial_negative() Function

PHP stats_rand_gen_ibinomial_negative() Function


Hello folks! welcome back to a new edition of our tutorial on PHP. In this tutorial guide, we are going to be discussing briefly about the stats_rand_gen_ibinomial_negative() function.

The stats_rand_gen_ibinomial_negative() function generates random deviate from the negative binomial distribution.

Syntax

Following below is the syntax to use this function -

int stats_rand_gen_ibinomial_negative( int $n, float $p )


Parameter Details

Sr.NoParameterDescription
1

n

The number of success

2

p

The success rate


Return Value

It returns a random deviate from negative binomial distribution where the number of success and the success rate is "n" and "p" respectively.

Dependencies

This built-in function was first introduced in statistics extension (PHP version 4.0.0 and PEAR v1.4.0). In this tutorial guide, we used the latest release of stats-2.0.3 (PHP v7.0.0 or newer and PEAR version 1.4.0 or newer).

Example1

In the following example, we compute the random deviation from the given negative binomial distribution where the number of success is 2, and the success rate is 0.5 -

<?php
   var_dump(is_int(stats_rand_ibinomial_negative(2, 0.5)));
?>

Output

When the above code is executed, it will produce the following result -

bool(true)

Example2

Following example below is an error case. In the below example, we have passed n < 0. A warning is shown in logs -

<?php
   // error cases
   var_dump(stats_rand_ibinomial_negative(-1, 0.5));   // n < 0
?>

Output

The above code will produce the following result and a warning in logs PHP Warning: stats_rand_ibinomial_negative(): n < 0. n: -1

bool(false)

Example3

Following example below is an error case. In the below example, we have passed pp < 0. A warning is shown in logs -

<?php
   // error cases
   var_dump(stats_rand_ibinomial_negative(1, -0.1));   // pp < 0
?>

Output

The above code will produce the following result and a warning in logs PHP Warning: stats_rand_ibinomial_negative(): p is out of range. p: -1E-1

bool(false)

Example4

Following example below is an error case. In the following example, we have passed pp > 1. A warning is shown in logs -

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

Output

The above code will produce the following result and a warning in logs PHP Warning: stats_rand_ibinomial_negative(): p is out of range. p: 1E+0.

bool(false)


Alright guys! This is where we are going to be rounding up for this tutorial post. In our next tutorial, we are going to be discussing about the stats_rand_gen_int() Function.

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