geometric_cdf

Evaluates the discrete geometric cumulative distribution function (CDF).

Synopsis

#include<imsls.h>

floatimsls_f_geometric_cdf(intix, floatpin)

The type double function is imsls_d_geometric_cdf.

Required Arguments

intix (Input)
Argument for which the discrete geometric CDF is to be evaluated. ix must be non-negative.

floatpin (Input)
Probability parameter of the discrete geometric CDF (the probability of success for each independent trial).   pin must be in the open interval (0, 1).

Return Value

The probability that a discrete geometric random variable takes a value less than or equal to ix. A value of NaN is returned if an input value is in error.

Description

The function geometric_cdf evaluates the discrete geometric cumulative distribution function (CDF), defined

 

where the return value F(I∣p) is the probability that up to I = ix trials would be observed before observing a success, and input parameter p = pin is the probability of success for each independent trial.

Example

In this example, we evaluate the discrete geometric CDF at ix = 3, pin = 0.25.

 

#include <imsls.h>

#include <stdio.h>

 

int main()

{

int ix = 3;

float pin = 0.25;

float p;

 

p = imsls_f_geometric_cdf(ix, pin);

printf("The probability that a discrete geometric ");

printf("random variable\nwith probability ");

printf("parameter pin = %4.2f is less than ", pin);

printf("or equal\nto %1i is %8.6f\n\n", ix, p);

}

Output

The probability that a discrete geometric random variable

with probability parameter pin = 0.25 is less than or equal

to 3 is 0.683594