Hi all, I understand that you most of you this is a peice of cake but i am a complete newbie in this....so any example would be greatly aprpeciated and also any hint as how to get around in R. Frankly i sometimes see the help files kinda confusing.
M -----Original Message----- From: Petr PIKAL [mailto:petr.pi...@precheza.cz] Sent: Thursday, November 04, 2010 3:40 PM To: Matevž Pavlič Cc: r-help@r-project.org Subject: Re: [R] Loop Hi r-help-boun...@r-project.org napsal dne 04.11.2010 14:21:38: > Hi David, > > I am still having troubles with that loop ... > > This code gives me (kinda) the name of the column/field in a data frame. Filed > names are form W1-W10. But there is a space between W and a number --> "W 10", > and column (field) names do not contain numbers. > > >for(i in 1:10) > >{ > >vari <- paste("W",i) > >} > >vari > > [1] "W 10" > > Now as i understand than i would call different columns to R with > > >w<-lit[[vari]] > > Or am i wrong again? > > Then I would probably need another loop to create the names of the variables > on R, i.e. w1 to w10. Is that a general idea for the procedure? Beware of such loops. Instead of littering your workspace with files/objects constructed by some paste(whatever, i) solution you can save results in list or data.frame or matrix and simply use basic subsetting procedures or lapply/sapply functions. I must say I never used such paste(...) construction yet and I work with R for quite a long time. Regards Petr > > > Thank for the help, m > > -----Original Message----- > From: David Winsemius [mailto:dwinsem...@comcast.net] > Sent: Wednesday, November 03, 2010 10:41 PM > To: Matevž Pavlič > Cc: r-help@r-project.org > Subject: Re: [R] Loop > > > On Nov 3, 2010, at 5:03 PM, Matevž Pavlič wrote: > > > Hi, > > > > Thanks for the help and the manuals. Will come very handy i am sure. > > > > But regarding the code i don't hink this is what i want....basically > > i > > would like to repeat bellow code : > > > > w1<-table(lit$W1) > > w1<-as.data.frame(w1) > > It appears you are not reading for meaning. Burns has advised you how > to > construct column names and use them in your initial steps. The `$` function is > quite limited in comparison to `[[` , so he was showing you a method that > would be more effective. BTW the as.data.frame step is unnecessary, since the > first thing write.table does is coerce an object to a data.frame. The > "write.table" name is misleading. It should be "write.data.frame". You cannot > really write tables with write.table. > > You would also use: > > file=paste(vari, "csv", sep=".") as the file argument to write.table > > > write.table(w1,file="w1.csv",sep=";",row.names=T, dec=".") > > What are these next actions supposed to do after the file is written? > Are you trying to store a group of related "w" objects that will later be > indexed in sequence? If so, then a list would make more sense. > > -- > David. > > > w1<- w1[order(w1$Freq, decreasing=TRUE),] w1<-head(w1, 20) > > > > 20 times, where W1-20 (capital letters) are the fields in a > > data.frame > > called "lit" and w1-20 are the data.frames being created. > > > > Hope that explains it better, > > > m > > > > -----Original Message----- > > From: Patrick Burns [mailto:pbu...@pburns.seanet.com] > > Subject: Re: [R] Loop > > > > If I understand properly, you'll want something like: > > > > lit[["w2"]] > > > > instead of > > > > lit$w2 > > > > more accurately: > > > > for(i in 1:20) { > > vari <- paste("w", i) > > lit[[vari]] > > > > ... > > } > > > > The two documents mentioned in my > > signature may help you. > > > > On 03/11/2010 20:23, Matevž Pavlič wrote: > >> Hi all, > >> > >> I managed to do what i want (with the great help of thi mailing > >> list) manually . Now i would like to automate it. I would probably > >> need a for loop for to help me with this...but of course I have no > >> idea how to do that in R. Bellow is the code that i would like to > >> be > >> replicated for a number of times (let say 20). I would like to > >> achieve that w1 would change to w2, w3, w4 ... up to w20 and by > >> that > >> create 20 data.frames that I would than bind together with cbind. > >> > >> (i did it like shown bellow -manually) > >> > >> w1<-table(lit$W1) > >> w1<-as.data.frame(w1) > >> write.table(w1,file="w1.csv",sep=";",row.names=T, dec=".") > >> w1<- w1[order(w1$Freq, decreasing=TRUE),] w1<-head(w1, 20) > >> > >> w2<-table(lit$W2) > >> > >> w2<-as.data.frame(w2) > >> > >> write.table(w2,file="w2.csv",sep=";",row.names=T, dec=".") > >> > >> w2<- w2[order(w2$Freq, decreasing=TRUE),] > >> > >> w2<-head(w2, 20) > >> . > >> . > >> . > >> > >> Thanks for the help,m > > > > > David Winsemius, MD > West Hartford, CT > > ______________________________________________ > 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.
