MaplePrimes - answers and comments on Question, Easiest Method for Random Variables?

ProbabilityFunction

Joe Riel — Sun, 20 Jan 2013 10:47:37 Z

with(Statistics):
X := RandomVariable(Binomial(10,1/2));
ProbabilityFunction(X,3);
                                      15
                                      ---
                                      128

For more complicated relations, use Probability

epostma — Thu, 24 Jan 2013 20:28:06 Z

Hi Bornin1992,

If you need to know the probability of more complicated events, you can use the ?Statistics/Probability command:

with(Statistics):
X := RandomVariable(Binomial(10, 1/2)):
Y := RandomVariable(Geometric(2/3)):
Probability(X + Y < 7);
# returns an exact fraction
Probability(X + Y < 7, 'numeric');
# returns 0.723...
# now to verify:
s := Sample(X + Y, 10^6):
SelectInRange(s, -infinity .. 6.999);
# should show a vector of roughly 723000 elements

Hope this helps,

Erik Postma
Maplesoft.

@Joe Riel Thank you, Joe!

Bornin1992 — Sun, 20 Jan 2013 11:19:20 Z

@Joe Riel

Thank you, Joe! This is exactly what I was looking for, and it appears to work for other distributions!