HI David, So if I understand from your post below, when we import a file in R- we need to make sure that the variable names do not have any space nor they should be in special characters or not in comma format. Please correct me I am wrong.
Now I have changed the file to a new file as RData.csv file and now when I use the below code it gives me an error graph<- read.csv("RData.csv", header = TRUE) MonthlyWeight<-by(RData$Weight,names.arg = RData$Month,sum) The error is : Error in by(RData$Weight, names.arg = RData$Month, sum) : object 'RData' not found. Whereas I checked using "getwd()" this file is saved in the working directory. Please suggest. -- View this message in context: http://r.789695.n4.nabble.com/Help-on-Histogram-Barplot-tp4707739p4707839.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.