[R] check for data in a data.frame and return correspondent number

[Jan van der Laan]

Marianna,

You can use merge for that (or match). Using merge:

MyData <- data.frame(
     V1=c("red-j", "red-j", "red-j", "red-j", "red-j", "red-j"),
     V4=c(10.5032, 9.3749, 10.2167, 10.8200, 9.2831, 8.2838),
     redNew=c("appearance blood-n", "appearance ground-n", "appearance 
sea-n", "appearance sky-n", "area chicken-n", "area color-n")
   )

MyVector <- data.frame(
     V1 = c("appearance blood-n", "appearance ground-n", "appearance 
sea-n", "as_adj_as fire-n", "as_adj_as carrot-n", "appearance sky-n", 
"area chicken-n", "area color-n")
   )


merge(MyVector, MyData[, c("V4", "redNew")] , by.x="V1", by.y="redNew", 
all.x=TRUE)


Btw I saw some spaces in some of your strings (I have removed these in 
the example above). Be aware that the character string "  appearance 
ground-n" is not equal to "appearance ground-n".

HTH
Jan





On 03/14/2012 06:49 PM, mari681 wrote:
> Dear R-ers,
>
> still the newbie. With a question about coordinates of a vector appearing or
> not in a data.frame.
> I have a data.frame (MyData) with 3 columns which looks like this:
>
>                         V1        V4              redNew
>                       red-j   10.5032      appearance blood-n
>                       red-j    9.3749       appearance ground-n
>                       red-j   10.2167      appearance sea-n
>                       red-j   10.8200      appearance sky-n
>                      red-j    9.2831       area chicken-n
>                      red-j    8.2838        area color-n
>
> and a MyVector  which includes also (but not only) the data in the 3rd
> column:
>
>                           " appearance blood-n"
>                          "  appearance ground-n"
>                            "appearance sea-n"
>                            "as_adj_as fire-n"
>                           "as_adj_as carrot-n"
>                           "appearance sky-n"
>                         " area chicken-n"
>                          "area color-n"
>
> I would like to get a data.frame of 2 columns where in the first column
> there is all MyVector, and in the second column  there is either the
> correspondent number found in MyData (shown in column 2) or a "0" if the
> entrance is not found.
>
> I've tried some options, among which a loop:
>
> out<-for(x in MyVector) if (x %in% MyData) print (MyData[,2])
>
> but obviously doesn't work.
> How can I select the correspondent element on column 2 for each x found in
> column 3?
>
> Suggestions in general?
> Thank you for consideration!!!
>
> Have a nice day,
> Marianna
>
>
> --
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> Sent from the R help mailing list archive at Nabble.com.
>
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