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IMSL_BETAI

Syntax | Return Value | Arguments | Keywords | Discussion | Example | Version History

The IMSL_BETAI function evaluates the real incomplete beta function.


Note
This routine requires an IDL Analyst license. For more information, contact your ITT Visual Information Solutions sales or technical support representative.

Syntax

Result = IMSL_BETAI(x, a, b [, /DOUBLE])

Return Value

The value of the incomplete beta function.

Arguments

x

Upper limit of integration.

a

First beta distribution parameter.

b

Second beta distribution parameter.

Keywords

DOUBLE

If present and nonzero, double precision is used.

Discussion

The incomplete beta function is defined as:

requiring that 0 £ x £ 1, a > 0, and b > 0. It underflows for sufficiently small x and large a. This underflow is not reported as an error. Instead, the value zero is returned.

Example

In this example, I0.61(2.2, 3.7) is computed and printed. 

PM, IMSL_BETAI(.61, 2.2, 3.7)  
     0.882172

Version History

6.4
Introduced

  IDL Online Help (March 06, 2007)