families {aster} | R Documentation |
Families (response models) known to the package. In all functions
families are specified by an integer index. families()
returns
names (as character strings) corresponding to valid index values.
For each family three functions are defined: the cumulant function for
the one-parameter exponential family, its first derivative (which maps
canonical parameter to mean value parameter), and its second derivative
(which maps canonical parameter to Fisher information).
families() famfun(index, deriv, theta)
index |
integer index of the family. |
deriv |
derivative wanted: 0, 1, or 2. |
theta |
value of the canonical parameter. |
Currently implemented families are
"bernoulli"
"poisson"
"non.zero.poisson"
tau = mu / (1 - exp(- mu)
The first derivative function has the value tau and the second derivative function has the value tau [1 - tau * exp(- mu)].
For families
a vector of character strings, each a family name.
For famfun
a scalar double, the value.
families() ### mean of poisson with mean 0.2 conditioned on being nonzero famfun(3, 1, log(0.2)) ### variance of poisson with mean 0.2 conditioned on being nonzero famfun(3, 2, log(0.2))