"Larry White" <[EMAIL PROTECTED]> writes: > hello, > > I'm trying to predict some values based on a linear regression model. > I've created the model using one dataframe, and have the prediction > values in a second data frame (call it newdata). There are 56 rows in > the dataframe used to create the model and 15 in newdata. > > I ran predict(model1, newdata) and get the warning: 'newdata' had 15 > rows but variable(s) found have 56 rows > > When i checked help(predict.lm) I found this: > > "Variables are first looked for in newdata and then searched for in > the usual way (which will include the environment of the formula used > in the fit). A warning will be given if the variables found are not of > the same length as those in newdata if it was supplied. " > > My questions are - how can I just get predicted values for the 15 rows > in the newdata data frame, and if that's not possible, how can I tell > which of the 56 predicted values are derived from newdata only, if > any.
You need to have all your predictors represented in newdata. You seem to have at least one of them missing (a typo in a variable name could do that). -- O__ ---- Peter Dalgaard Øster Farimagsgade 5, Entr.B c/ /'_ --- Dept. of Biostatistics PO Box 2099, 1014 Cph. K (*) \(*) -- University of Copenhagen Denmark Ph: (+45) 35327918 ~~~~~~~~~~ - ([EMAIL PROTECTED]) FAX: (+45) 35327907 ______________________________________________ [email protected] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
