Hi Henrik, Thanks for testing it to a different dataset. I didn't test it at that time to multiple conditions. Probably, apply is a better method.
Anyway, you can still get the same result by doing this: dat1<-read.table(text=" Lat Lon x1 x2 x3 01 10 NA NA .1 01 11 .4 NA .3 01 12 NA .5 .6 ",sep="",header=TRUE) dat2<-data.frame(t(dat1[,3:5])) dat3<-data.frame(dat1,NewColumn=unlist(lapply(dat2,function(x) x[!is.na(x)][1]))) row.names(dat3)<-1:nrow(dat3) dat3 # Lat Lon x1 x2 x3 NewColumn #1 1 10 NA NA 0.1 0.1 #2 1 11 0.4 NA 0.3 0.4 #3 1 12 NA 0.5 0.6 0.5 #Now, to a slightly different dataset dat1<-read.table(text=" Lat Lon x1 x2 x3 01 10 NA NA NA 01 11 NA NA .3 01 12 NA .6 NA ",sep="",header=TRUE) dat2<-data.frame(t(dat1[,3:5])) dat3<-data.frame(dat1,NewColumn=unlist(lapply(dat2,function(x) x[!is.na(x)][1]))) row.names(dat3)<-1:nrow(dat3) dat3 #Lat Lon x1 x2 x3 NewColumn #1 1 10 NA NA NA NA #2 1 11 NA NA 0.3 0.3 #3 1 12 NA 0.6 NA 0.6 I hope this works well. A.K. ----- Original Message ----- From: Henrik Singmann <henrik.singm...@psychologie.uni-freiburg.de> To: arun <smartpink...@yahoo.com> Cc: Camilo Mora <cm...@dal.ca>; R help <r-help@r-project.org> Sent: Tuesday, July 24, 2012 10:18 AM Subject: Re: First value in a row Hi, As Arun's idea was also my first idea let me pinpoint the problem of this solution. It only works if the data in question (i.e., columns x1 to x3) follow the pattern of the example data insofar that the NAs form a triangle like structure. This is so because it loops over columns instead of rows and takes advantage of the triangle NA structure. For example, slightly changing the data leads to a result that does not follow the description of Camilo seem to want: dat1<-read.table(text=" Lat Lon x1 x2 x3 01 10 NA NA .1 01 11 .4 NA .3 01 12 NA .5 .6 ",sep="",header=TRUE) # correct answer from description would be .1, .4, .5 # arun's solution: data.frame(dat1,NewColumn=rev(unlist(lapply(dat1[,3:5],function(x) x[!is.na(x)][1])))) # x3 x2 x1 # 0.1 0.5 0.4 # my solution: apply(dat1[,-(1:2)], 1, function(x) x[!is.na(x)][1]) # [1] 0.1 0.4 0.5 So the question is, what you want and how the data looks. Cheers, Henrik Am 24.07.2012 14:27, schrieb arun: > Hi, > > Try this: > > dat1<-read.table(text=" > Lat Lon x1 x2 x3 > 01 10 NA NA .1 > 01 11 NA .2 .3 > 01 12 .4 .5 .6 > ",sep="",header=TRUE) > > dat2<-dat1[,3:5] > dat3<-data.frame(dat1,NewColumn=rev(unlist(lapply(dat2,function(x) >x[!is.na(x)][1])))) > row.names(dat3)<-1:nrow(dat3) > dat3 > Lat Lon x1 x2 x3 NewColumn > 1 1 10 NA NA 0.1 0.1 > 2 1 11 NA 0.2 0.3 0.2 > 3 1 12 0.4 0.5 0.6 0.4 > > A.K. > > > > > ----- Original Message ----- > From: Camilo Mora <cm...@dal.ca> > To: r-help@r-project.org > Cc: > Sent: Tuesday, July 24, 2012 2:48 AM > Subject: [R] First value in a row > > Hi. > > This is likely a trivial problem but have not found a solution. Imagine the > following dataframe: > > Lat Lon x1 x2 x3 > 01 10 NA NA .1 > 01 11 NA .2 .3 > 01 12 .4 .5 .6 > > I want to generate another column that consist of the first value in each row > from columns x1 to x3. That is > > NewColumn > .1 > .2 > .4 > > Any input greatly appreciated, > > Thanks, > > Camilo > > > Camilo Mora, Ph.D. > Department of Geography, University of Hawaii > > ______________________________________________ > 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. > > -- Dipl. Psych. Henrik Singmann PhD Student Albert-Ludwigs-Universität Freiburg, Germany http://www.psychologie.uni-freiburg.de/Members/singmann ______________________________________________ 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.
