Download a complete copy of this risk
analysis resource for free here.
|
Format: VoseMultinomial(n,{pi})
The Multinomial distribution is a multivariate distribution is used to describe how many independent trials will fall into each of several categories where the probability of falling into any one category is constant for all trials.
As such, it is an extension of the Binomial distribution where there are only two possible outcomes ('successes' and, by implication, 'failures').
For example, consider the action people might take on entering a shop:
Code |
Action |
Probability |
A1 |
Enter and leave without purchase or sample merchandise |
32% |
A2 |
Enter and leave with a purchase |
41% |
A3 |
Enter and leave with sample merchandise |
21% |
A4 |
Enter to return a product and leave without purchase |
5% |
A5 |
Enter to return a product and leave with a purchase |
1% |
If 1000 people enter a shop, how many will match each of the above actions?
The answer is
{VoseMultinomial(1000,{32%, 41%, 21%, 5%, 1%})}
which is an array function that generates five separate values. The sum of those five values must, of course, always add up to the number of trials (1000 in this example).
VoseMultinomial generates values from this distribution
VoseMultinomialProb returns the probability density or cumulative distribution function for this distribution
VoseMultinomialProb10 returns the log10 of the probability density or cumulative distribution function
