Hi, Try: df$POT2_TX<- df$POT_TX df[,6:7]<- lapply(df[,6:7],function(x) as.numeric(as.character(sub(",",".",x)))) str(df) #'data.frame': 10 obs. of 7 variables: # $ IDANT : int 37837 37838 37839 37840 37841 37842 37843 40720 40721 40722 # $ N_TX : int 6 6 6 4 1 1 1 2 2 1 # $ TILT : int 0 0 0 0 6 6 6 0 0 0 # $ DIREZIONE: int 50 220 110 50 220 110 50 170 70 270 # $ DATA_INI : Factor w/ 2 levels "20/10/2004","29/08/2002": 2 2 2 2 2 2 2 1 1 1 # $ POT_TX : num 8 8 8 4 11.5 11.5 11.5 10 10 10 # $ POT2_TX : num 8 8 8 4 11.5 11.5 11.5 10 10 10 A.K.
----- Original Message ----- From: "mbres...@arpa.veneto.it" <mbres...@arpa.veneto.it> To: David Winsemius <dwinsem...@comcast.net> Cc: r-help@r-project.org; maxbre <mbres...@arpa.veneto.it> Sent: Friday, August 9, 2013 3:35 PM Subject: Re: [R] decimal separator from comma to dot This is my reproducible example df<-structure(list(IDANT = c(37837L, 37838L, 37839L, 37840L, 37841L, 37842L, 37843L, 40720L, 40721L, 40722L), N_TX = c(6L, 6L, 6L, 4L, 1L, 1L, 1L, 2L, 2L, 1L), TILT = c(0L, 0L, 0L, 0L, 6L, 6L, 6L, 0L, 0L, 0L), DIREZIONE = c(50L, 220L, 110L, 50L, 220L, 110L, 50L, 170L, 70L, 270L), DATA_INI = structure(c(2L, 2L, 2L, 2L, 2L, 2L, 2L, 1L, 1L, 1L), .Label = c("20/10/2004", "29/08/2002" ), class = "factor"), POT_TX = structure(c(4L, 4L, 4L, 3L, 2L, 2L, 2L, 1L, 1L, 1L), .Label = c("10", "11,5", "4", "8"), class = "factor")), .Names = c("IDANT", "N_TX", "TILT", "DIREZIONE", "DATA_INI", "POT_TX"), row.names = c(NA, 10L), class = "data.frame") from david winsemius reply (quite annoyed by me, sorry for that!) http://r.789695.n4.nabble.com/decimal-separator-from-comma-to-dot-td4673414.html#a4673461 and from faq 7.10 I learnt this is the correct way to perform the conversion from factor to number for a single variable df$POT_TX <- as.numeric(as.character( sub(",", ".", df$POT_TX ))) but what about the case of more than one column (variable) in a data frame? I hope now my question is fine with the rules of this mailing list thank you all for the patiente I'm learning a lot max ______________________________________________ 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.