I'm trying to follow this guide here: http://www.ats.ucla.edu/stat/r/modules/dummy_vars.htm
In which I'm creating categorical variables using the factor function. I am able to go through the example listed above and have everything work, however, when I try to input my own numbers, I get an error. I input the following: > hits = read.csv(file.choose()) > attach(hits) > day.f <- factor(day) > lm(write ~ (day.f)) lm(write ~ (day.f)) Error in model.frame.default(formula = write ~ (day.f), drop.unused.levels = > TRUE) : > object is not a matrix > So I import "hits = read.csv(file.choose())" a .csv file, which has the columns "visits" and "day" where "visits" is the number of hits to a website, and "day" is a number 1-7, for example 1 corresponds to Sunday and 7 corresponds to Saturday. I understand that the day variable needs to be a categorical variable, and I'm trying to use the factor function to do this. I would like to be able to run a regression that will correlate the day with the number of hits. Any help would be much appreciated. [[alternative HTML version deleted]] ______________________________________________ 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.