[R] Question about predict.glm

Prof Brian D Ripley ripley at stats.ox.ac.uk
Sat Jul 8 20:08:58 CEST 2000

On Sat, 8 Jul 2000 brian_adams at jbadams.com wrote:

> I am trying to use predict.glm to validate a logistic model.  Using
> predictions <- predict.glm(logit.model, type="response",
> dataframe="validate")
> I get the predictions from the original dataframe, not the validation
> data frame.  Am I missing an input to the method or is this what is
> supposed to happen?

The argument is `newdata'.  ?predict.glm seems clear enough to me
(but then I wrote it).


     predict.glm(object, newdata = NULL, type = c("link", "response", 
                 se.fit = FALSE, dispersion = NULL, terms = NULL, ...)


  object: a fitted object of class inheriting from `"glm"'.

 newdata: optionally, a new data frame from which to make the
          predictions.  If omitted, the fitted linear predictors are

so I think it is working as documented ....

Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272860 (secr)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595

r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html
Send "info", "help", or "[un]subscribe"
(in the "body", not the subject !)  To: r-help-request at stat.math.ethz.ch

More information about the R-help mailing list