Displaying 1 result from an estimated 1 matches for "testddply".
2009 Nov 19
1
Performance of 'by' and 'ddply' on a large data frame
...enough, not sure why this is, the result of by with the min
function is not date objects but instead integers representing days
from an origin. Is there a min function that would return me a date
instead of an integer? Or is this a result of using by?
I also wanted to see how ddply compares.
> testddply <- function(p) { pdf <- randomdf(p); system.time(ddply(pdf, .(x1), function(df) { return (data.frame(min(df$x2))) })) }
> lapply(c(1,2,3,4,5), testddply)
[[1]]
user system elapsed
0.020 0.000 0.021
[[2]]
user system elapsed
0.119 0.000 0.119
[[3]]
user system elap...