Functions and CALL Routines

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
Arguments
Details
Comparisons
See Also

Syntax

RANTRI(seed,h)

Arguments

seed

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

Range:	seed < 2³¹-1
See:	Seed Values for more information about 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 [le] C [le] 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.