UNDF

This function evaluates the uniform cumulative distribution function.

Function Return Value

UNDF — Function value, the probability that a uniform random variable takes a value less than or equal to X. (Output)

Required Arguments

X — Argument for which the uniform cumulative distribution function is to be evaluated. (Input)

A — Location parameter of the uniform cumulative distribution function. (Input)

B — Value used to compute the scale parameter (B ‑ A) of the uniform cumulative distribution function. (Input)

FORTRAN 90 Interface

Generic: UNDF (X, A, B)

Specific: The specific interface names are S_UNDF and D_UNDF.

FORTRAN 77 Interface

Single: UNDF (X, A, B)

Double: The double precision name is DUNDF.

Description

The function UNDF evaluates the uniform cumulative distribution function with location parameter A and scale parameter (B ‑ A). The function definition is

 

Example

In this example, we evaluate the probability function at X = 0.65, A = 0.25, B = 0.75.

 

USE UMACH_INT

USE UNDF_INT

IMPLICIT NONE

INTEGER NOUT

REAL X, A, B, PR

CALL UMACH(2, NOUT)

X = 0.65

A = 0.25

B = 0.75

PR = UNDF(X, A, B)

WRITE (NOUT, 99999) X, A, B, PR

99999 FORMAT (' UNDF(', F4.2, ', ', F4.2, ', ', F4.2, ') = ', F6.4)

END

Output

 

UNDF(0.65, 0.25, 0.75) = 0.8000