I have a data set that has 4 columns and 53860858 rows. I was able to read this into R with:
cc <- rep("character",4) myData <- read.table("myData.csv",header=FALSE,skip=1,colClasses=cc,nrow=53860858,sep=",") I need to reshape this data from long to wide. On a small data set the following lines work. But on the real data set, it didn't finish even when I took a sample of two (rows in new data). I didn't receive an error. I just stopped it because it was taking too long. Any suggestions for improvements? Thanks. # start example # i have commented out the write.table statement below testData <- read.table(textConnection("rs9999853,cv0084,A,A rs999986,cv0084,C,B rs9999883,cv0084,E,F rs9999853,cv0085,G,H rs999986,cv0085,I,J rs9999883,cv0085,K,L"),header=FALSE,sep=",") closeAllConnections() mysamples <- unique(testData$V2) for (one_ind in mysamples) { one_sample <- testData[testData$V2==one_ind,] mywide <- reshape(one_sample, timevar = "V1", idvar = "V2",direction = "wide") # write.table(mywide,file ="newdata.txt",append=TRUE,row.names=FALSE,col.names=FALSE,quote=FALSE) } ______________________________________________ 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.