[R] help in merging

[Gabor Grothendieck]

Not sure if its guaranteed but this sqlite join does seem to preserve
the order of the first data frame.

> library(sqldf)
> BOD
  Time demand
1    1    8.3
2    2   10.3
3    3   19.0
4    4   16.0
5    5   15.6
6    7   19.8
> BODrev <- BOD[6:1,]; BODrev
  Time demand
6    7   19.8
5    5   15.6
4    4   16.0
3    3   19.0
2    2   10.3
1    1    8.3
> sqldf("select * from BODrev, BOD using(Time)")
  Time demand demand
1    7   19.8   19.8
2    5   15.6   15.6
3    4   16.0   16.0
4    3   19.0   19.0
5    2   10.3   10.3
6    1    8.3    8.3

See home page at: http://sqldf.googlecode.com


On Thu, Dec 24, 2009 at 2:26 PM,  <utkarsh.singhal at global-analytics.com> wrote:
>
>   Hi All,
>   I want to "merge" two datasets by column "ID" and I don't want the result to
>   be sorted by "ID". I am doing the following:
>   > z = merge(x, y, by = "ID", sort=F)
>   The result is not sorted by "ID". But (as oppose to what I expected) it is
>   not even in the original order of either "x" or "y".
>   Can somebody tell what to do if I wanted it to be in the original order of
>   x.
>
>   P.S.: As my dataset is very huge and I couldn't find the right subset of the
>   data which explains the above problem, so I can't attach it at the moment.
>   If anybody knows the answer, please reply; or else I will try to get the
>   right subset.
>
>   Thanks in advance
>
>   Utkarsh
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