rpart.poisson {rpart} | R Documentation |
Set up for poisson
method for an rpart
model.
rpart.poisson(y, offset, parms, wt)
y |
the responses, a vector or a two-column matrix. If a matrix the first column is the observation times and the second is the counts. |
offset |
an offset, or NULL . The offset is interpreted as
a log observation time. |
parms |
a list of parameters. |
wt |
case weights. |
rpart.poisson
is to be used only by the function rpart
.
Returns a list consisting of
y |
a matrix giving the observation times and number of events, |
parms |
a named list of parameters, with components shrink
and method (1 for "deviance" , 2 for "sqrt" ), |
numresp |
the number of responses, here 2 , |
numy |
the number of columns in y , here 2 , |
summary |
a function to be invoked by summary.rpart , |
text |
a function to be invoked by text.rpart . |