Functions and CALL Routines 
Category:  Random Number 
Syntax  
Arguments  
Details  
Comparisons  
Examples  
See Also 
Syntax 
CALL RANBIN(seed,n,p,x); 
is the seed value. A new value for seed is returned each time CALL RANBIN is executed.
Range:  seed < 2^{31}  1 
Note:  If seed 0, the time of day is used to initialize the seed stream. 
See:  Seed Values and Comparison of Seed Values in RandomNumber Functions and CALL Routines for more information about seed values 
is an integer number of independent Bernoulli trials.
Range:  n > 0 
is a numeric probability of success parameter.
Range:  0<p<1 
is a numeric SAS variable. A new value for the random variate x is returned each time CALL RANBIN is executed.
Details 
The CALL RANBIN routine updates seed and returns a variate x that is generated from a binomial distribution with mean np and variance np(1p). If n 50, np 5, or n(1p) 5, SAS uses an inverse transform method applied to a RANUNI uniform variate. If n>50, np>5, and n(1p)>5, SAS uses the normal approximation to the binomial distribution. In that case, the BoxMuller transformation of RANUNI uniform variates is used.
By adjusting the seeds, you can force streams of variates to agree or disagree for some or all of the observations in the same, or in subsequent, DATA steps.
For a discussion and example of an effective use of the random number CALL routines, see Starting, Stopping, and Restarting a Stream.
Comparisons 
The CALL RANBIN routine gives greater control of the seed and random number streams than does the RANBIN function.
Examples 
The following example uses the CALL RANBIN routine:
options pageno=1 nodate ls=80 ps=64; data u1 (keep = x); seed = 104; do i = 1 to 5; call ranbin(seed, 2000, 0.2 ,x); output; end; call symputx('seed', seed); run; data u2 (keep = x); seed = &seed; do i = 1 to 5; call ranbin(seed, 2000, 0.2 ,x); output; end; run; data all; set u1 u2; z = ranbin(104, 2000, 0.2); run; proc print label; label x = 'Separate Streams' z = 'Single Stream'; run;
Output from the CALL RANBIN Routine
The SAS System 1 Separate Single Obs Streams Stream 1 423 423 2 418 418 3 403 403 4 394 394 5 429 429 6 369 369 7 413 413 8 417 417 9 400 400 10 383 383
See Also 

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