Displaying 1 result from an estimated 1 matches for "by_sorted".
2006 Jul 27
6
Any interest in "merge" and "by" implementations specifically for sorted data?
...ast but the first "by"
statement was still running 4 hours later on my machine (a dual 2.6
gig Opteron with 4 gig of main memory). This same snippet of code in
SAS running on a slower machine takes about 5 minutes of system time.
I tried various simple R implementations of a "by_sorted" that I
thought might help
# walk sorted array once and keep track of beginning
# and ending points for each unique sort key value in p
# and run function fcn on that sub sequence in vector v
# store the results in a vector
by_sorted <- function(v, p, fcn) {
key <- p[[1]]
bp...