R help - Sep 2008 - Newbie: Ranking a data frame, grouped by 2 or more columns

Hi,

I'd like to rank obs in a data frame as subset by 2 or more columns...
The example input would look like the following:

====+====+====+====+
x   y   v
--  --  --
a   w   200
a   w   100
b   w   500
b   w   200
b   z   300
b   z   400
====+====+====+====+

And the data frame I want to create is below:
====+====+====+====+
x   y   v   rank
--  --  --  ----
a   w   200    1
a   w   100    2
b   w   500    1
b   w   200    2
b   z   300    2
b   z   400    1
====+====+====+====+

Can someone help me with this?

Thanks,
Matt
-- 
It is from the wellspring of our despair and the places that we are
broken that we come to repair the world.
-- Murray Waas

Try this:

DF
  V1 V2  V3
1  a  w 200
2  a  w 100
3  b  w 500
4  b  w 200
5  b  z 300
6  b  z 400

DF$rank <- unlist(lapply(split(DF$V3, list(DF$V1, DF$V2), drop = T), rank))




On Fri, Sep 26, 2008 at 5:54 PM, Matthew Pettis
<matthew.pettis at gmail.com> wrote:
> Hi,
>
> I'd like to rank obs in a data frame as subset by 2 or more columns...
> The example input would look like the following:
>
> ====+====+====+====+
> x   y   v
> --  --  --
> a   w   200
> a   w   100
> b   w   500
> b   w   200
> b   z   300
> b   z   400
> ====+====+====+====+
>
> And the data frame I want to create is below:
> ====+====+====+====+
> x   y   v   rank
> --  --  --  ----
> a   w   200    1
> a   w   100    2
> b   w   500    1
> b   w   200    2
> b   z   300    2
> b   z   400    1
> ====+====+====+====+
>
> Can someone help me with this?
>
> Thanks,
> Matt
> --
> It is from the wellspring of our despair and the places that we are
> broken that we come to repair the world.
> -- Murray Waas
>
> ______________________________________________
> R-help at 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.
>


-- 
Henrique Dallazuanna
Curitiba-Paran?-Brasil
25? 25' 40" S 49? 16' 22" O

On Fri, Sep 26, 2008 at 3:54 PM, Matthew Pettis
<matthew.pettis at gmail.com> wrote:
> Hi,
>
> I'd like to rank obs in a data frame as subset by 2 or more columns...
> The example input would look like the following:
>
> ====+====+====+====+
> x   y   v
> --  --  --
> a   w   200
> a   w   100
> b   w   500
> b   w   200
> b   z   300
> b   z   400
> ====+====+====+====+
>
> And the data frame I want to create is below:
> ====+====+====+====+
> x   y   v   rank
> --  --  --  ----
> a   w   200    1
> a   w   100    2
> b   w   500    1
> b   w   200    2
> b   z   300    2
> b   z   400    1
> ====+====+====+====+
>
> Can someone help me with this?
This is easy to do with the (very soon to be released) plyr package:

library(plyr)
ddply(df, .(x, y), transform, rank = rank(v))

You can learn more about it at http://had.co.nz/plyr

Hadley

-- 
http://had.co.nz/

Try this:
> x
  V1 V2  V3
1  a  w 200
2  a  w 100
3  b  w 500
4  b  w 200
5  b  z 300
6  b  z 400
> x$rank <- ave(x$V3, x$V1, x$V2, FUN=rank)
> x
  V1 V2  V3 rank
1  a  w 200    2
2  a  w 100    1
3  b  w 500    2
4  b  w 200    1
5  b  z 300    1
6  b  z 400    2
>

On Fri, Sep 26, 2008 at 4:54 PM, Matthew Pettis
<matthew.pettis at gmail.com> wrote:
> Hi,
>
> I'd like to rank obs in a data frame as subset by 2 or more columns...
> The example input would look like the following:
>
> ====+====+====+====+
> x   y   v
> --  --  --
> a   w   200
> a   w   100
> b   w   500
> b   w   200
> b   z   300
> b   z   400
> ====+====+====+====+
>
> And the data frame I want to create is below:
> ====+====+====+====+
> x   y   v   rank
> --  --  --  ----
> a   w   200    1
> a   w   100    2
> b   w   500    1
> b   w   200    2
> b   z   300    2
> b   z   400    1
> ====+====+====+====+
>
> Can someone help me with this?
>
> Thanks,
> Matt
> --
> It is from the wellspring of our despair and the places that we are
> broken that we come to repair the world.
> -- Murray Waas
>
> ______________________________________________
> R-help at 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.
>


-- 
Jim Holtman
Cincinnati, OH
+1 513 646 9390

What is the problem that you are trying to solve?