Hello Please see the example below> class(testX)[1] "matrix"> class(testX[1,])[1] "numeric" Why not matrix? What am I missing here? Is there a way to keep the same class? The reason for the question is that I want to implement a k-step ahead prediction for my own routines and R wrecks does not seem to like [1,] as shown below.> predict(fit10,testX[1,])Error in knnregTrain(train = c(1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, : dims of 'test' and 'train differ> predict(fit10,testX[1:2,])[1] 81.00 76.36 Many thanks Ed [[alternative HTML version deleted]]
Try this: predict(fit10,testX[1,,drop = FALSE]) On Fri, Sep 2, 2011 at 5:05 PM, Eduardo M. A. M.Mendes <emammendes at gmail.com> wrote:> Hello > > > > Please see the example below > > > >> class(testX) > > [1] "matrix" > >> class(testX[1,]) > > [1] "numeric" > > > > Why not matrix? ? What am I missing here? ? Is there a way to keep the same > class? > > > > The reason for the question is that I want to implement a k-step ahead > prediction for my own routines and R wrecks does not seem to like [1,] as > shown below. > > > >> predict(fit10,testX[1,]) > Error in knnregTrain(train = c(1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, ?: > ?dims of 'test' and 'train differ >> predict(fit10,testX[1:2,]) > [1] 81.00 76.36 > > > > Many thanks > > > > Ed > > > > > ? ? ? ?[[alternative HTML version deleted]] > > ______________________________________________ > R-help at 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. >-- Henrique Dallazuanna Curitiba-Paran?-Brasil 25? 25' 40" S 49? 16' 22" O
On Sep 2, 2011, at 3:05 PM, Eduardo M. A. M.Mendes wrote:> Hello > > > > Please see the example below > > > >> class(testX) > > [1] "matrix" > >> class(testX[1,]) > > [1] "numeric" > > > > Why not matrix? What am I missing here? Is there a way to keep the same > class? > > > > The reason for the question is that I want to implement a k-step ahead > prediction for my own routines and R wrecks does not seem to like [1,] as > shown below. > > > >> predict(fit10,testX[1,]) > Error in knnregTrain(train = c(1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, : > dims of 'test' and 'train differ >> predict(fit10,testX[1:2,]) > [1] 81.00 76.36 > > > > Many thanks > > > > EdEd, See: http://cran.r-project.org/doc/FAQ/R-FAQ.html#Why-do-my-matrices-lose-dimensions_003f and then use: predict(fit10, testX[1, , drop = FALSE]) HTH, Marc Schwartz