Re: [R] eliminating constant variables

2010-07-12 Thread Setlhare Lekgatlhamang
What was the question and answer here? -Original Message- From: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] On Behalf Of pdb Sent: Sunday, July 11, 2010 5:23 AM To: r-help@r-project.org Subject: Re: [R] eliminating constant variables Importance: Low Awsome! It

Re: [R] eliminating constant variables

2010-07-10 Thread pdb
Awsome! It made sense once I realised SD=standard deviation ! pdb -- View this message in context: http://r.789695.n4.nabble.com/eliminating-constant-variables-tp2284831p2284915.html Sent from the R help mailing list archive at Nabble.com. __ R-help

Re: [R] eliminating constant variables

2010-07-10 Thread Gabor Grothendieck
On Sat, Jul 10, 2010 at 6:28 PM, pdb wrote: > > Hi all, > > I have a large data set and want to immediately build a 'blind' model > without first examining the data. Now it appears in the data there are a lot > of fields that are constant or all missing values - which prevents the model > from bei

Re: [R] eliminating constant variables

2010-07-10 Thread pdb
Yep - that is what I want. Cheers Jim you Legend. -- View this message in context: http://r.789695.n4.nabble.com/eliminating-constant-variables-tp2284831p2284861.html Sent from the R help mailing list archive at Nabble.com. __ R-help@r-project.org ma

Re: [R] eliminating constant variables

2010-07-10 Thread jim holtman
Is this what you want: > test <- data.frame(a=runif(10), b=rep(NA, 10), c=rep(3,10), d=runif(10)) > test a b c d 1 0.3390729 NA 3 0.4346595 2 0.8394404 NA 3 0.7125147 3 0.3466835 NA 3 0.344 4 0.3337749 NA 3 0.3253522 5 0.4763512 NA 3 0.7570871 6 0.8921983 NA 3 0.20269

Re: [R] eliminating constant variables

2010-07-10 Thread pdb
Hi Jim, Thanks for your response, although I was probably not clear about exactly what I want to achieve, please let me see if I can explain a little better... There are certain (unknown) columns in my data that contain either NULL in every row, or the same value in every row (eg '1'). These co

Re: [R] eliminating constant variables

2010-07-10 Thread jim holtman
You can remove NAs with: train <- subset(train, !is.na(TargetVariable)) I am not sure what you mean by constant values. You could use 'table' to determine which values appear the most and then remove them: x <- table(train$TargetVariable) train <- subset(train, !(TargetVariable %in% names(x)[x

[R] eliminating constant variables

2010-07-10 Thread pdb
Hi all, I have a large data set and want to immediately build a 'blind' model without first examining the data. Now it appears in the data there are a lot of fields that are constant or all missing values - which prevents the model from being built. Can someone point me the right direction as to