predictInt: Prediction Inteval for Quantile Regression
Description
Predicts future values using the median and finds a prediction interval for future values using an upper and lower quantile. The lower quantile is (1-level)/2 and the upper quantile is .5 + level/2.
Usage
predictInt(fit, level=.95, newdata=NULL, ...)
Arguments
fit
a fitted model of class "plaqr" or "rq" to be used for prediction.
level
the prediction level required. The lower quantile is (1-level)/2 and the upper quantile is .5 + level/2.
newdata
an optional data frame in which to look for variables with which
to predict. If omitted, the fitted values are used.
...
additional argument(s) for methods.
Value
a matrix with columns giving the predicted median and lower and upper prediction bounds.