I am a very novice R user, a social scientist (linguist) who is trying to learn to use R after being very familiar with SPSS. Please be kind!
My concern: I cannot figure out a way to get an accurate count of observations of one column of data split by a factor when there are NAs in the data. I know how to use commands like tapply and summaryBy to obtain other summary statistics I am interested in, such as the following: tapply(RLWTEST, list(STATUS), mean, na.rm=T) summaryBy(RLWTEST~STATUS, data=lh.forgotten, FUN=c(mean, sd, min, max), na.rm=T) However, with tapply I know I cannot use length to get a count where there are NAs. summaryBy appears to work the same way. I do know how to get a count of the entire column using sum: sum(!is.na(lh.forgotten$RLWTEST)) However, this does not give me a count split up by my factor (STATUS). I have looked through Daalgard (2002) and Verzani (2005), and have searched the help files, but with no luck. Thank you in advance for your help. I love R and am interested in making it more accessible to social scientist types like me. I know it can do everything SPSS can and more, but sometimes the very simplest things seem to be a lot harder in R. Jenifer Dr. Jenifer Larson-Hall Assistant Professor of Linguistics University of North Texas (940)369-8950 ______________________________________________ [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
