[R] Perform operations on dataframes called with paste in loops

Greg Snow Greg.Snow at imail.org
Wed Nov 18 22:03:54 CET 2009


There are a few options:

You can read the help page for the function that you used to assign names to the data frames when you read them in (the 'see also' section is there for a reason).

You can read the FAQ (7.21 to be specific, but the others could save you re-asking FAQs in the future)

You can take a better approach by reading all your data sets into a list (use lapply on the vector of names), then use lapply on the list of datasets and avoid all the future headache/heartache that will come from the approach you are trying.

-- 
Gregory (Greg) L. Snow Ph.D.
Statistical Data Center
Intermountain Healthcare
greg.snow at imail.org
801.408.8111


> -----Original Message-----
> From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-
> project.org] On Behalf Of separent
> Sent: Tuesday, November 17, 2009 4:15 PM
> To: r-help at r-project.org
> Subject: [R] Perform operations on dataframes called with paste in
> loops
> 
> 
> In a loop, I compose the name of a csv file using paste, then read it
> (e.g.,
> dataset1.csv, dataset2.csv, etc). The name of the dataframe assigned to
> the
> imported csv is also composed with paste (e.g., dataset1, dataset2,
> etc.).
> Now I want to perform operations on the dataframes dataset1, dataset2,
> etc.
> However, the paste function only renders a string on which I can not,
> for
> example, do operations like
> plot(paste("dataset",i,"[,1]",sep=""),paste("dataset",i,"[,2]",sep=""))
> . How
> could I call the dataframe instead of the string representing its name?
> --
> View this message in context: http://old.nabble.com/Perform-operations-
> on-dataframes-called-with-paste-in-loops-tp26399586p26399586.html
> Sent from the R help mailing list archive at Nabble.com.
> 
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