# [EMAIL PROTECTED]
`predict' complains about new factor levels, even if the "new" levels are
merely levels in the original that didn't occur in the original fit and were
sensibly dropped, and that don't occur in the prediction data either. (At
least if `drop.unused.levels' was set to TRUE, which the default.)
test> scrunge.data.2_ data.frame( y=runif( 3), disc=factor( c( 'cat', 'dog',
'cat'), levels=c( 'cat', 'dog', 'earwig')))
test> lm.predbug.2_ lm( y~disc, data=scrunge.data.2)
test> predict(lm.predbug.2, newdata=scrunge.data.2)
Error in model.frame.default(object, data, xlev = xlev) :
factor disc has new level(s) earwig
A cure for this seems to be to add the commented line below towards the end
of `model.frame.default':
<<...>>
if (length(xlev) > 0) {
for (nm in names(xlev)) if (!is.null(xl <- xlev[[nm]])) {
xi <- data[[nm]]
if (is.null(nxl <- levels(xi)))
warning(paste("variable", nm, "is not a factor"))
else {
xi <- xi[, drop = TRUE]
nxl <- levels( xi) # MVB: remove droppees
if (any(m <- is.na(match(nxl, xl))))
stop(paste("factor", nm, "has new level(s)", nxl[m]))
}
}
}
else if (drop.unused.levels) {
<<...>>
cheers
Mark
*******************************
Mark Bravington
CSIRO (CMIS)
PO Box 1538
Castray Esplanade
Hobart
TAS 7001
phone (61) 3 6232 5118
fax (61) 3 6232 5012
[EMAIL PROTECTED]
--please do not edit the information below--
Version:
platform = i386-pc-mingw32
arch = i386
os = mingw32
system = i386, mingw32
status =
major = 1
minor = 6.2
year = 2003
month = 01
day = 10
language = R
Windows 2000 Professional (build 2195) Service Pack 3.0
Search Path:
.GlobalEnv, ROOT, package:handy, package:debug, mvb.session.info,
package:mvbutils, package:tcltk, Autoloads, package:base
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