Gamma distribution

Menu location: Analysis_Distributions_Gamma.

The gamma distribution depends upon two parameters; A (the shaping parameter) and B (the scaling parameter).

The gamma density function is:

$image\STAT0091_wmf.gif$ , t ³ 0

The gamma function G (*) is:

$image\STAT0092_wmf.gif$ , x > 0

If A is an integer then G(A)=(A-1)! where x! is factorial x.

When A = 1 this gives an exponential distribution. If you vary A then the shape of the distribution will change. Changing B does not affect the shape of the distribution, just its scale on the x axis.

See random number fill.