functions in random.i - p

    poisson(navg)  


returns a Poisson distributed random value with mean NAVG.  
(This is the integer number of events which actually occur  
 in some time interval, when the probability per unit time of  
 an event is constant, and the average number of events during  
 the interval is NAVG.)  
The return value has the same dimensions as the input NAVG.  
The return value is an integer, but its type is double.  
The algorithm is taken from Numerical Recipes by Press, et. al.  
Interpreted function, defined at i/random.i   line 524