R programming: Can you use dplyr to apply a function to every row or column like apply(base) or ddply(plyr)? [closed]
group_by(dplyr) is great but you can't group_by every column or row, you can only group by a couple variables. that's my understanding. I want to apply a function to every single variable of a ...
Sometimes I need to get only the first row of a data set grouped by an identifier, as when retrieving age and gender when there are multiple observations per individual. What's a fast (or the fastest) ...
I want to calculate a summary of a variable in a data.frame for each unique combination of factors in the data.frame. Should I use plyr to do this? I am ok with using loops as opposed to apply() ; so ...