Hi, You could try: cumsum(c(1,abs(diff(as.numeric(factor(v1)))))) # [1] 1 1 1 2 2 3 3 3 3 4 A.K.
----- Original Message ----- From: Arnaud Michel <michel.arn...@cirad.fr> To: PIKAL Petr <petr.pi...@precheza.cz> Cc: R help <r-help@r-project.org> Sent: Monday, July 22, 2013 11:41 AM Subject: Re: [R] Calculate interaction for a big dataframe 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 >> >> ______________________________________________ >> 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. -- 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. ______________________________________________ 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.
