search for: 800967

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2009 Feb 27
3
Making tapply code more efficient
...r better efficiency. I was quite embarrased on this as our SAS programmers cranked out programs that did this in the blink of an eye (with a few variables), but R was spinning for days on my Ubuntu machine and ultimately I saw a message that R was "killed". The data I am working with has 800967 total rows and 31 total columns. The ID variable I use as the index variable in tapply() has 326397 unique cases. > length(unique(qq$student_unique_id)) [1] 326397 To give a sense of what my data look like and the actual problem, consider the following: qq <- data.frame(student_unique_id =...