Dear All, I have many 50 objects they are all dataframes. Each dataframe has many rows and four column. I simply want to do an addition of 3rd and 4th column and save the result into 5th column. Since there are many dataframes, I don't want to do it one by one, is there a way to loop through all objects and perform the similar action ?
One way I can think of is like this: for (i in 1:50){ get(ls()[i])[,3]+get(ls()[i][,4] } But I don't know how to save the addition result back to 5th column of each dataframe. Many Thanks! Stephen HK Wong ______________________________________________ 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.