Hi, I would appreciate some help with using grep(). I have a bunch of variables in a data frame and I would like to select some of them using grep. Here is an example of what I am trying to do:
vars <- c("Fr_I_total", "Fr_I_percent_of_CD4", "Ki.67_in_Fr_I_percent_of_Fr_I", "Fr_II_percent_of_CD4", "Ki.67_in_Fr_II_percent_of_Fr_II") >From the above vector, I would like to select those variables beginning with >`Fr' and containing `percent' in them. In other words, I would like to get >the variables "Fr_I_percent_of_CD4" and "Fr_II_percent_of_CD4". How can I use grep() to do this? More generally, are there any good online resources with examples like this for the use of grep() and regexp() in R? I didn't find the help pages for these very user-friendly. Thank you very much, Ravi Ravi Varadhan, Ph.D. (Biostatistics), Ph.D. (Environmental Engg) Associate Professor, Department of Oncology Division of Biostatistics & Bionformatics Sidney Kimmel Comprehensive Cancer Center Johns Hopkins University 550 N. Broadway, Suite 1111-E Baltimore, MD 21205 410-502-2619 [[alternative HTML version deleted]] ______________________________________________ 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.