Dear R Users,
I am trying to get the following to work better:
namevec <- c("one", "two", "three")
for (name in namevec) {
namedf <- eval(parse(text=paste(name, "_df",
sep="")))
...
...
}
The rationale behind it being that I created variables with names
one_df, two_df and three_df earlier in the same script which I want to
reference inside the for loop. Is there a more elegant way to do this?
Best Regards,
Michael Bach
On Fri, Apr 29, 2011 at 1:03 PM, Michael Bach <phaebz at gmail.com> wrote:> Dear R Users, > > I am trying to get the following to work better: > > namevec <- c("one", "two", "three") > for (name in namevec) { > ? ?namedf <- eval(parse(text=paste(name, "_df", sep=""))) > ? ?... > ? ?... > } > > The rationale behind it being that I created variables with names > one_df, two_df and three_df earlier in the same script which I want to > reference inside the for loop. ?Is there a more elegant way to do this?Yes, one elegant way to do it would be using a named list instead of separate variables. X <- list() X$one_df <- "something" X[["two_df"]] <- "something else" NAME <- "one_df" X[[NAME]] NAME <- "two_df" X[[NAME]] #etc # the for loop could then be: for(name in names(X)) ... or for(element in X) Another way (not elegant but better and shorter than the eval-parse way) is to use get. ?get Best regards, Kenn
Hi Michael.
This is a classic :-)
ObjectsOfInterest<- list(one_df, two_df, three_df)
for(namedf in ObjectsOfInterest){...}
or probably even better
sapply(ObjectsOfInterest, function(namedf){...})
hth.
Nick Sabbe
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-----Original Message-----
From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org]
On
Behalf Of Michael Bach
Sent: vrijdag 29 april 2011 12:03
To: r-help at r-project.org
Subject: [R] Reference variables by string in for loop
Dear R Users,
I am trying to get the following to work better:
namevec <- c("one", "two", "three")
for (name in namevec) {
namedf <- eval(parse(text=paste(name, "_df",
sep="")))
...
...
}
The rationale behind it being that I created variables with names
one_df, two_df and three_df earlier in the same script which I want to
reference inside the for loop. Is there a more elegant way to do this?
Best Regards,
Michael Bach
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