Thank you Petr
paste is better than interaction for long vectors
But now a new problem/question is appeared.
Now, I would like transform the vector
v1 <- c(
"4162.France", "4162.France", "4162.France",
"4162.Mali", "4162.Mali",
"4162.France", "4162.France", "4162.France", "4162.France",
"4162.Mali")
into a vector V2 with the same length but with number which are creasing
v2 <- c(1, 1, 1,
2, 2,
3, 3,3,3,
4))
Any idea (function) ?
Regards
Le 22/07/2013 14:45, PIKAL Petr a écrit :
Hi
you maybe could use paste
f1<-sample(letters[1:3], 10, replace=T)
f2<-sample(letters[4:7], 10, replace=T)
f3<-sample(letters[9:11], 10, replace=T)
interaction(f1, f2, f3, drop=T)
[1] c.e.j b.e.j a.e.j c.g.i a.f.j b.g.k a.e.i a.e.k a.d.j b.e.j
Levels: a.e.i c.g.i a.d.j a.e.j b.e.j c.e.j a.f.j a.e.k b.g.k
paste(f1, f2, f3, sep=".")
[1] "c.e.j" "b.e.j" "a.e.j" "c.g.i" "a.f.j" "b.g.k" "a.e.i" "a.e.k" "a.d.j"
[10] "b.e.j"
The difference is that interaction gives you directly factor, paste gives you
character vector, but it may be convenient too for your purpose.
Regards
Petr
-----Original Message-----
From: r-help-boun...@r-project.org [mailto:r-help-bounces@r-
project.org] On Behalf Of Arnaud Michel
Sent: Monday, July 22, 2013 10:57 AM
To: R help
Subject: [R] Calculate interaction for a big dataframe
Hi
To calculate the value of the interaction between factors of a
dataframe df, does exist any function which could replace the function
when the dataframe df has the numbers of rows of df is large (~55000)
and also the numbers of combinaison of the three factors is large. The
calcul abort.
The function to calculate the interaction is :
as.numeric(interaction(df [,c(1:3)],drop=TRUE))
To complete the question and to calculate interaction beetween 3
factors f1, f2, f3, does it possible to calculate first f12 =
interaction
(f1,f2) and after calculate interaction (f12, f3).
It seems to me that yes.
Thanks for your help
--
Michel ARNAUD
Chargé de mission auprès du DRH
DGDRD-Drh - TA 174/04
Av Agropolis 34398 Montpellier cedex 5
tel : 04.67.61.75.38
fax : 04.67.61.57.87
port: 06.47.43.55.31
______________________________________________
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PLEASE do read the posting guide http://www.R-project.org/posting-
guide.html
and provide commented, minimal, self-contained, reproducible code.
--
Michel ARNAUD
Chargé de mission auprès du DRH
DGDRD-Drh - TA 174/04
Av Agropolis 34398 Montpellier cedex 5
tel : 04.67.61.75.38
fax : 04.67.61.57.87
port: 06.47.43.55.31
______________________________________________
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.