simplex {VGAM} | R Documentation |
The two parameters of the univariate simplex distribution are estimated.
simplex(lmu = "logit", lsigma = "loge", emu=list(), esigma=list(), imu = NULL, isigma = NULL)
lmu |
Link function for mu .
See Links for more choices.
The parameter lies in the unit interval.
|
lsigma |
Link function for sigma .
See Links for more choices.
The parameter is positive, therefore the log link is the default.
|
emu, esigma |
List. Extra argument for each of the links.
See earg in Links for general information.
|
imu, isigma |
Optional initial values for mu and sigma .
A NULL means a value is obtained internally.
|
See Jorgensen (1997) for details.
An object of class "vglmff"
(see vglmff-class
).
The object is used by modelling functions such as vglm
,
and vgam
.
This distribution is potentially useful for dispersion modelling.
This family function only works for intercept-only models, i.e.,
the formula should have ~ 1
.
T. W. Yee
Jorgensen, B. (1997) The Theory of Dispersion Models. London: Chapman & Hall
rig
.
x = runif(n <- 100) y = rbeta(n, shape1=3+x, shape2=4-x) (fit = vglm(y ~ 1, simplex, trace=TRUE, cri="coef")) coef(fit, matrix=TRUE) Coef(fit) summary(fit)