Or have a look at tapply(). > -----Original Message----- > From: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] > On Behalf Of Pascal Oettli > Sent: Saturday, October 13, 2012 22:16 > To: GradStudentDD > Cc: r-help@r-project.org > Subject: Re: [R] Replace column values in R conditional on values from > different column > > Hello, > > No need for a loop. "else if" doesn't exist in R. And Health2$CohenM and > Health2_CohenF have to be created first, in case of a loop > > If Health2$q_5a only have 1 and 2 as possible values, just use "which" > and "-". And I would suggest to not add new variables in your data frame, > because you will include some NA. Create 2 new variables, then do your > different calculations on. > > CohenM <- Health2$CohenSum[w] > CohenF <- Health2$CohenSum[-w] > > Regards > Pascal > > > Le 12/10/13 20:59, GradStudentDD a écrit : > > Dear List, > > > > I am working on a stats project and have been stumped by the issue of > > replacing values in a column conditional on values from a different column. > > I searched the forum and google in general, and was able to put some > > code together, but it's not working the way it's supposed to... I > > appreciate any help you can offer! A detailed description of the > > issue, and the code I came up with, is below. > > > > I am trying to separate one variable (CohenSum) into separate values > > for males and females, in two separate columns, so I can do > > computations on them (i.e. mean, sd). I tried the code below, but the > > values I got didn't make sense - the length of the M and F columns > > should have been about half of the initial column length and NA for > > the rest (I have about half men and half women in the sample) but > > instead every cell has values in it, except for the initial NAs. I > > think R somehow inserted 0 instead of NAs for the gender values which > > were not supposed to be in that column (i.e. replaced values for females > with 0 in the male column) but I don't know why. > > > > Thanks!!!!! > > > > for(i in 1:length(Health2$CohenSum)){ > > if (Health2$q_5a[i]==1) Health2$CohenM[i] <- Health2$CohenSum[i] > > else if (Health2$q_5a[i]==2) Health2$CohenF[i] <- Health2$CohenSum[i] > > else Health2$CohenF[i] <- NA > > } > > > > > > > > -- > > View this message in context: > > http://r.789695.n4.nabble.com/Replace-column-values-in-R-conditional-o > > n-values-from-different-column-tp4646087.html > > Sent from the R help mailing list archive at Nabble.com. > > > > ______________________________________________ > > 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. > > > > ______________________________________________ > 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.
______________________________________________ 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.
