Why not use an indicator variable? P1 <- ... # prediction from model 1 (Setosa) for entire dataset
P2 <- ... # prediction from model 2 for entire dataset I <- Species=="setosa" # Predictions <- P1 * I + P2 * ( 1 - I ) On Monday, December 10, 2012, Brian Feeny wrote: > > I have a dataset and I wish to use two different models to predict. Both > models are SVM. The reason for two different models is based > on the sex of the observation. I wish to be able to make predictions and > have the results be in the same order as my original dataset. To > illustrate I will use iris: > > # Take Iris and create a dataframe of just two Species, setosa and > versicolor, shuffle them > data(iris) > iris <- iris[(iris$Species=="setosa" | iris$Species=="versicolor"),] > irisindex <- sample(1:nrow(iris), nrow(iris)) > iris <- iris[irisindex,] > > # Make predictions on setosa using the mySetosaModel model, and on > versicolor using the myVersicolorModel: > > predict(mySetosaModel, iris[iris$Species=="setosa",]) > predict(myVersicolorModel, iris[iris$Species=="versicolor",]) > > The problem is this will give me a vector of just the setosa results, and > then one of just the versicolor results. > > I wish to take the results and have them be in the same order as the > original dataset. So if the original dataset had: > > > Species > setosa > setosa > versicolor > setosa > versicolor > setosa > > I wish for my results to have: > <prediction for setosa> > <prediction for setosa> > <prediction for versicolor> > <prediction for setosa> > <prediction for versicolor> > <prediction for setosa> > > But instead, what I am ending up with is two result sets, and no way I can > think of to combine them. I am sure this comes up alot where you have a > factor you wish to split your models on, say sex (male vs. female), and you > need to present the results back so it matches to the order of the orignal > dataset. > > I have tried to think of ways to use an index, to try to keep things in > order, but I can't figure it out. > > Any help is greatly appreciated. > > Brian > > ______________________________________________ > R-help@r-project.org <javascript:;> 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. > > > [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org 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.
