For lpstr1: the same idea as zipoisson
except it applies to a structural 1.
ilambda, gpstr1, gprobs.y, imethod
For initial values.
See CommonVGAMffArguments for information.
type.fitted, zero
See CommonVGAMffArguments for information.
Details
The 1-inflated positive Poisson distribution is a mixture
distribution of the
positive (0-truncated) Poisson
distribution with some probability of obtaining a (structural) 1.
Thus there are two sources for obtaining the value 1.
It is similar to a zero-inflated Poisson model, except
the Poisson is replaced by a positive Poisson and the 0 is replaced
by 1.
This distribution is written here
in a way that retains a similar notation to the
zero-inflated Poisson, i.e., the
probability P[Y=1] involves another parameter phi.
See zipoisson.
This family function can handle multiple responses.
Value
An object of class "vglmff" (see vglmff-class).
The object is used by modelling functions such as vglm,
rrvglm and vgam.
Warning
Under- or over-flow may occur if the data is ill-conditioned.