Antwort: Fw: Re: Creating variables on the fly (SOLVED)
Hi Don,
Hi to all readers,
many thanks for all your answers and all your help.
I adapted Don's code to my data and Don's code does the trick:
str(Kunden01)
for (year in 2011:2015) {
Reeller_Kunde <- paste0("Reeller_Kunde_", year)
Umsatz <- paste0("Umsatz_", year)
cat('Creating', Reeller_Kunde,'from', Umsatz,'\n')
Kunden01[[ Reeller_Kunde ]] <- ifelse( Kunden01[[ Umsatz ]] >= 0, 1, 2)
Kunden01[[ Reeller_Kunde ]] <- factor( Kunden01[[ Reeller_Kunde ]],
levels=c(1,2),
labels= c("NICHT kaufend",
"kaufend")
)
}
str(Kunden01)
This way a new variable is created by building it from a string
concatenation.
I also like the cat() function to document the process within the loop
while running the program.
Many thanks for your help.
Kind regards
Georg
Von: G.Maubach at gmx.de
An: g.maubach at weinwolf.de,
Datum: 25.04.2016 21:37
Betreff: Fw: Re: [R] Creating variables on the fly
Gesendet: Montag, 25. April 2016 um 19:35 Uhr Von: "MacQueen, Don" <macqueen1 at llnl.gov> An: "G.Maubach at gmx.de" <G.Maubach at gmx.de>, "r-help at r-project.org"
<r-help at r-project.org>
Betreff: Re: [R] Creating variables on the fly
I'm going to assume that Kunden is a data frame, and it has columns
(variables) with names like
Umstatz_2011
and that you want to create new columns with names like
Kunde_real_2011
If that is so, then try this (not tested):
for (year in 2011:2015) {
nmK <- paste0("Kunde_real_", year)
nmU <- paste0("Umsatz_", year)
cat('Creating',nmK,'from',nmU,'\n')
Kunden[[ nmK ]] <- ifelse( Kunden[[ nmU ]] <= 0, 1, 2)
Kunden[[ nmK ]] <- factor( Kunden[[ nmK ]],
levels=c(1,2),
labels= c("NICHT kaufend", "kaufend")
)
}
This little example should illustrate the method:
foo <- data.frame(a=1:4) foo
a 1 1 2 2 3 3 4 4
foo[['b']] <- foo[['a']]*3 foo
a b 1 1 3 2 2 6 3 3 9 4 4 12 -- Don MacQueen Lawrence Livermore National Laboratory 7000 East Ave., L-627 Livermore, CA 94550 925-423-1062 On 4/22/16, 8:52 AM, "R-help on behalf of G.Maubach at gmx.de" <r-help-bounces at r-project.org on behalf of G.Maubach at gmx.de> wrote:
Hi all,
I would like to use a loop for tasks that occurs repeatedly:
# Groups
# Umsatz <= 0: 1 (NICHT kaufend)
# Umsatz > 0: 2 (kaufend)
for (year in c("2011", "2012", "2013", "2014", "2015")) {
paste0("Kunden$Kunde_real_", year) <- (paste0("Kunden$Umsatz_", year)
<= 0) * 1 +
(paste0("Kunden$Umsatz_", year)
0) * 2
paste0("Kunden$Kunde_real_", year) <- factor(paste0("Kunden$Umsatz_",
year),
levels = c(1, 2),
labels = c("NICHT
kaufend", "kaufend"))
}
This actually does not work due to the fact that the expression
"paste0("Kunden$Kunde_real_", year)" ist not interpreted as a variable
name by the R script language interpreter.
Is there a way to assembly variable names on the fly in R?
Regards
Georg
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