RANTRI Function

Returns a random variate from a triangular distribution.

Category:	Random Number
Tip:	If you want to change the seed value during execution, you must use the CALL RANTRI routine instead of the RANTRI function.

Syntax

RANTRI(seed,h)

Required Arguments

seed

is a numeric constant, variable, or expression with an integer value. If seed ≤ 0, the time of day is used to initialize the seed stream.

Range	seed < 2³¹−1
See	for more information about seed values.Seed Values

h

is a numeric constant, variable, or expression that specifies the mode of the distribution.

Range

0 < h < 1

Details

The RANTRI function returns a variate that is generated from the triangular distribution on the interval (0,1) with parameter h, which is the modal value of the distribution. An inverse transform method applied to a RANUNI uniform variate is used.

A triangular distribution X on the interval (A,B) with mode C, where A ≤ C ≤ B, can be generated:

x=(b-a)*rantri(seed,(c-a)/(b-a))+a;

For a discussion about seeds and streams of data, as well as examples of using the random-number functions, see Generating Multiple Variables from One Seed in Random-Number Functions.

Comparisons

The CALL RANTRI routine, an alternative to the RANTRI function, gives greater control of the seed and random number streams.