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RANEXP 
Category:  Random Number 
Tip:  If you want to change the seed value during execution, you must use the CALL RANEXP routine instead of the RANEXP function. 
Syntax  
Arguments  
Details  
Comparisons  
See Also 
Syntax 
RANEXP(seed) 
Range:  seed < 2^{31}1 
Note:  If seed 0, the time of day is used to initialize the seed stream. 
Details 
The RANEXP function returns a variate that is generated from an exponential distribution with parameter 1. An inverse transform method applied to a RANUNI uniform variate is used.
An exponential variate X with parameter LAMBDA can be generated:
x=ranexp(seed)/lambda;
An extreme value variate X with location parameter ALPHA and scale parameter BETA can be generated:
x=alphabeta*log(ranexp(seed));
A geometric variate X with parameter P can be generated as follows:
x=floor(ranexp(seed)/log(1p));
Comparisons 
The CALL RANEXP routine, an alternative to the RANEXP function, gives greater control of the seed and random number streams.
See Also 
Call routine:

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Copyright 1999 by SAS Institute Inc., Cary, NC, USA. All rights reserved.