Question

I have a data frame with multiple columns, one of which (called: drift.N) is a series of TRUE’s and FALSES’s. How would I go about separating the “TRUE” rows from the “FALSE” rows or asking R to tell me which rows drift.N==”TRUE” ?

Answer 1

If you have a data.frame called df:

df[df$column_name,]

gets you the subset of the data.frame where column_name equals TRUE. To get the FALSE subset:

df[!df$column_name,]

(spot the exclamation mark !), where ! is NOT. To get the indices where column_name is TRUE:

which(df$column_name)
which(!df$column_name)

Finally, I recommend you go online and download some basic R tutorials and work through them. This questions, and many other basics, will be treated in them. See e.g.:

• http://www.cyclismo.org/tutorial/R/
• http://cran.r-project.org/manuals.html