Dear all, I found the answer: intersect()
- John On Thu, May 21, 2009 at 7:32 PM, tsunhin wong <[email protected]> wrote: > Dear Jim, > Thanks for your suggestion. > > I have a follow-up question for fellow R Users that have followed this thread: > > *I used to create two lists by some very flexible criteria to compare > from "iData" and pass the two lists to *ANOTHER FUNCTION* that further > decompose the two lists and do some case by case analysis: > > comp.lst[[1]] <- subset(iData,(Session==1 & TrialList==2 & BadTrial==0 > & Correct==1 & Critical.BT>0)) > comp.lst[[2]] <- subset(iData,(Session==2 & TrialList==2 & BadTrial==0 > & Correct==1 & Critical.BT>0)) > > *The function will then do some subject by subject processing: > > tmplist <- comp.lst[[1]] > subject <- unique(tmplist$Subject) > Psubjmatrix <- NULL > for(j in 1:length(subj)) { ##divide the list and process per subject in the > list > subjtriallist <- subset(tmplist,(Subject==subj[j])) ##divide > the list and process per subject in the list > print(paste("Start working on Subject ",subj[j],sep=""),quote=FALSE) > ##The sub-divided list is passed to another function to > extract data from corresponding object > Ptrialmatrix <- SeekObject(subjtriallist,seconds,samplesize,sdmax); > ##add rowmean to subject pupil matrix > Psubjmatrix <- cbind(Psubjmatrix, rowMeans(Ptrialmatrix, > na.rm=TRUE, dims=1)) > } > > *But now, I have a pre-processed the objects and cooked up a > 1500x20000 matrix, and there is no need to get these objects one by > one for extraction, I may just do the following: > > Ptrialmatrix <- PMasterMatrix[subjindex,,drop=FALSE] > > *However, on passing the index to the function, I cannot further > sub-divide the list index by Subject. > > I have been thinking of passing the criteria to within the function. > But... what smarter thing I can do to make it works? > > - John > > > On Thu, May 21, 2009 at 10:33 AM, jim holtman <[email protected]> wrote: >> Assuming that you get the list of indices into iData for the criteria, then >> you can use that to get the appropriate rows: >> >> indx <- which(iData >5) # or whatever your criteria is >> DataSeq[indx,, drop=FALSE] # gives you a subset matrix of just the rows you >> are interested in. >> >> On Thu, May 21, 2009 at 10:10 AM, tsunhin wong <[email protected]> wrote: >>> >>> Dear R Users, >>> >>> I have created a 1500 x 20000 data frame - DataSeq. Each of the 1500 >>> rows represents a data sequence. >>> I have another data frame iData that stores the information of these >>> 1500 data sequences in the same order, for example, condition, gender, >>> etc. >>> >>> If I use "subset" to select certain groups within iData according to >>> some criteria that I have set, e.g. condition, gender >>> Then how can I used the retrieved subset of iData to point to and >>> retrieve corresponding rows in the DataSeq data.frame for >>> manipulations and analysis? >>> >>> I hope some of you can give me some idea! >>> Thank you very much!!! >>> >>> - John >>> >>> ______________________________________________ >>> [email protected] 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. >> >> >> >> -- >> Jim Holtman >> Cincinnati, OH >> +1 513 646 9390 >> >> What is the problem that you are trying to solve? >> > ______________________________________________ [email protected] 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.
