TITLE(family @@ Family Objects for Models)
USAGE(
family(object)
BLANK
binomial(link=logit)
gaussian()
Gamma(link=inverse)
inverse.gaussian()
poisson(link=log)
quasi(link=identity, variance=constant)
)
ALIAS(family)
ALIAS(binomial)
ALIAS(gaussian)
ALIAS(Gamma)
ALIAS(inverse.gaussian)
ALIAS(poisson)
ALIAS(quasi)
ARGUMENTS(
ARG(link @@ a specification for the model link function.
The LANG(binomial) family admits the links; LANG(logit),
LANG(probit) and LANG(cloglog) (complementary log-log),
the LANG(Gamma) family the links; LANG(identity),
LANG(inverse) and LANG(log),
the LANG(poisson) family the links; LANG(identity)
LANG(log) and LANG(sqrt), and
the LANG(quasi) family the links; LANG(logit),
LANG(probit), LANG(cloglog),  LANG(identity), LANG(inverse),
LANG(log), LANG(1/mu^2) and LANG(sqrt).
The other families have only a single permissible
link function.  These are the LANG(identity) for the LANG(gaussian)
family and LANG(1/mu^2) for the LANG(inverse.gaussian) family.
The function LANG(power) can also be used to create a
power link function for the LANG(quasi) family.)
ARG(variance @@ for all families, other than LANG(quasi),
the variance function is determined by the family.
The LANG(quasi) family will accept the specifications
LANG(constant), LANG(mu(1-mu)), LANG(mu), LANG(mu^2) and
LANG(mu^3) as variance function.)
ARG(object @@ the function LANG(family) accesses the
LANG(family) objects which are stored within objects
created by modelling functions (e.g. LANG(glm)).)
)
DESCRIPTION(
Family objects provide a convenient way to specify
the details of the models used by functions such as LANG(glm).
See the documentation for LANG(glm) for the details on
how such model fitting takes place.
)
REFERENCES(
McCullagh P. and J. A. Nelder (1989).
ITALIC(Generalized Linear Models).
London: Chapman and Hall.
PARA
Dobson, A. J. (1983).
ITALIC(An Introduction to Statistical Modelling).
London: Chapman and Hall.
PARA
Cox, D. R. and E. J. Snell (1981).
ITALIC(Applied Statistics; Principles and Examples).
London: Chapman and Hall.
)
SEEALSO(
LANG(LINK(glm)), LANG(LINK(power)).
)
