Please read and in the future follow the Posting Guide, which requests that you
provide a reproducible example... that is, a series of R statements that we can
run to get us to your problem point with a small sample data set that resembles
yours. Forging on anyway...
The ifelse function applies to vectors, not data frames. That is, as long as
both data frames have the same number of rows, you should be able to do things
like
CurrentDataFrame$Name <- ifelse( CurrentDataFrame$Name=="NA",
PastDataFrame$Name, CurrentDataFrame$Name)
Please note that NA is completely different than "NA" (read the Introduction to
R document that comes with R if you need a refresher). If you are really trying
to weed out NA values then you would need to do something like
CurrentDataFrame$Name <- ifelse( is.na(CurrentDataFrame$Name),
PastDataFrame$Name, CurrentDataFrame$Name)
Also, if you need speed or are pushing the limits of your RAM, the following
approach avoids replacing the entire vector:
idx <- is.na(CurrentDataFrame$Name)
CurrentDataFrame[idx,"Name"] <- PastDataFrame[idx,"Name"]
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On March 26, 2014 9:44:06 AM PDT, Megan Weigel <mw5w...@gmail.com> wrote:
>Hello,
>
>Hopefully there is an answer for this, but I need an ifelse statement
>that
>replaces and returns a value based on a different dataframe. For
>example:
>
>CurrentDataFrame<-ifelse(CurrentDataFrame$Name=="NA",match(CurrentDataFrame$Code
>with PastDataFrame$Code),replace(CurrentDataFrame$Name) with
>(PastDataFrame$Name)
>
>
>I hope that makes sense.
>
>Thank you very much,
>
>Johnson
>
> [[alternative HTML version deleted]]
>
>______________________________________________
>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.
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and provide commented, minimal, self-contained, reproducible code.
