[R] Basic data frame manipulation

[Ista Zahn]

Something like

tmp <- merge(df1, df2, by = "row.names", all.x = TRUE)
merge(tmp, df3, by.x = "Row.names", by.y = "row.names", all.x = TRUE)

perhaps?



On Mon, Feb 23, 2015 at 4:25 PM, Jon BR <jonsleepy at gmail.com> wrote:
> Hi R-help,
>     Although I know that variations of this question are frequently asked,
> I searched and haven't found an answer for this specific variant, and
> wonder if any of you know this off the top of your head:
>
> df1 <- data.frame(a = 1:5,
>                   row.names = letters[1:5]) # letters a to e
> df2 <- data.frame(a = 1:5,
>                   row.names = letters[3:7]) # letters c to g
> df3 <- data.frame(a = 1:5,
>                   row.names = letters[c(1,2,3,5,7)]) # letters a, b, c, e,
> and g
>
>
> I would like a command to produce a data frame which contains the same rows
> (with rownames) as in df1, with elements in the columns corresponding to
> the values present in each of the data frames (if there exists a matching
> row; else NA if not present).  This should ideally work even if the rows
> are in random order and if not sorted.
>
> The result would look something like this:
>
> df1.a df2.a df3.a
> a 1 NA 1
> b 2 NA 2
> c 3 1 3
> d 4 2 NA
> e 5 3 4
>
> Thank you in advance for any tips.
>
> Jonathan
>
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>
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