Beta Distribution

These functions give you access to the Beta distribution. For more information about Fathom's distribution functions, click here.

 

betaDensity(x, shP, shQ, min, max)

betaCumulative(x, shP, shQ, min, max)

betaQuantile(x, shP, shQ, min, max)

 shP = shape parameter, >0
shQ =
shape parameter, >0
min =
minimum
max =
maximum

The density, cumulative, and quantile functions for the beta distribution. The density distribution extends only over the interval [min, max], or [0,1] if you use the defaults.

The shP and shQ shape parameters are required and must both be positive. They determine the shape of the distribution. The larger they are, the skinnier the distribution. The mean is shP / (shP + shQ), so if shP > shQ, its mean is more than 0.5.

defaults: center = 0, scale = 1, min = 0, max = min + 1.

You may also draw random values from this distribution:

randomBeta(shP, shQ, min, max)

A random value drawn from that distribution.

 

Here are some density functions illustrating the meaning of the parameters:

 

See also statistical functions (for mean( ) and its cousins).