First thing to do is to use Rprof to determine where the time is being
spent and then you can pinpoint what section of code is taking the
time. A quick look says to do all your subsetting at once. You might
look into using 'split' to create the subsets and then access the
subsets with "[[...]]".
Dear R-users,
I have written the following code to generate some trellis plots. It
works perfectly fine except that it is quite slow when it is apply to my
typical datasets (over several thousands of lines). I believe the
problem comes from the loops I am using to subset my data.frame. I read
