Hello,
I created a data.frame which contains two columns: df$P (Power) et
df$DateTime (time). I'd like to add a new column df$diffP (difference of
Power between T and T-2).
I made a loop :
for (i in 3:length(df$DateTime)){
df$diffP[i] = df$P[i] - df$P[i-2]
}
execution time result is unaceptable: 24s !!
Is there any way to reduce complexity about O(n) ? for example 2 or 3s (10s
maxi)
Does anybody find better than ~24s ?
thanks for your help
--
View this message in context:
http://r.789695.n4.nabble.com/data-frame-temporal-complexity-tp4269585p4269585.html
Sent from the R help mailing list archive at Nabble.com.
______________________________________________
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
