Extract various types of predictions from beta regression models:
either on the scale of responses in (0, 1) or the scale of
the linear predictor.
Usage
## S3 method for class 'betareg'
predict(object, newdata = NULL,
type = c("response", "link", "precision", "variance", "quantile"),
na.action = na.pass, at = 0.5, ...)
Arguments
object
fitted model object of class "betareg".
newdata
optionally, a data frame in which to look for variables with
which to predict. If omitted, the original observations are used.
type
character indicating type of predictions: fitted means of response ("response"),
corresponding linear predictor ("link"), fitted precision parameter
phi ("precision"), fitted variances of response ("variance"),
or fitted quantile(s) of the response distribution ("quantile").
na.action
function determining what should be done with missing values
in newdata. The default is to predict NA.
at
numeric vector indicating the level(s) at which quantiles
should be predicted (only if type = "quantile"), defaulting
to the median at = 0.5.
...
currently not used.
Examples
data("GasolineYield", package = "betareg")
gy2 <- betareg(yield ~ batch + temp | temp, data = GasolineYield)
cbind(
predict(gy2, type = "response"),
predict(gy2, type = "link"),
predict(gy2, type = "precision"),
predict(gy2, type = "variance"),
predict(gy2, type = "quantile", at = c(0.25, 0.5, 0.75))
)