R help - May 2005 - question about subset

Dear R users:

I have a quick question:

is there any way to get a subset of a data frame with the ordered indexes or
without these indexes?

example:

mydata<- data.frame(A=seq(1,10), B=c(-5,2,-4,6,-8,-9,2,5,7,0))
subset(mydata, B>0)
  A B
2 2 2
4 4 6
7 7 2
8 8 5
9 9 7

I would like to obtain this:

  A B
1 2 2
2 4 6
3 7 2
4 8 5
5 9 7

or this

  A B
  2 2
  4 6
  7 2
  8 5
  9 7

I think this is possible but I dont know how...
any sugestion?
thanks

jose silva
	[[alternative HTML version deleted]]

?row.names

-- Bert Gunter
Genentech Non-Clinical Statistics
South San Francisco, CA
 
"The business of the statistician is to catalyze the scientific learning
process."  - George E. P. Box
 
 
> -----Original Message-----
> From: r-help-bounces at stat.math.ethz.ch 
> [mailto:r-help-bounces at stat.math.ethz.ch] On Behalf Of jose silva
> Sent: Thursday, May 05, 2005 3:31 PM
> To: r-help at stat.math.ethz.ch
> Subject: [R] question about subset
> 
> Dear R users:
> 
> I have a quick question:
> 
> is there any way to get a subset of a data frame with the 
> ordered indexes or without these indexes?
> 
> example:
> 
> mydata<- data.frame(A=seq(1,10), B=c(-5,2,-4,6,-8,-9,2,5,7,0))
> subset(mydata, B>0)
> ?? A B
> 2 2 2
> 4 4 6
> 7 7 2
> 8 8 5
> 9 9 7
> 
> I would like to obtain this:
> 
> ?? A B
> 1 2 2
> 2 4 6
> 3 7 2
> 4 8 5
> 5 9 7
> 
> or this
> 
> ?? A B
> ????2 2
> ????4 6
> ????7 2
> ????8 5
> ????9 7
> 
> I think this is possible but I dont know how...
> any sugestion?
> thanks
> 
> jose silva
> 	[[alternative HTML version deleted]]
> 
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide! 
> http://www.R-project.org/posting-guide.html
>

On May 5, 2005, at 6:31 PM, jose silva wrote:
> rois there any way to get a subset of a data frame with the ordered 
> indexes or without these indexes?
>
> example:
>
> mydata<- data.frame(A=seq(1,10), B=c(-5,2,-4,6,-8,-9,2,5,7,0))
> subset(mydata, B>0)
>   A B
> 2 2 2
> 4 4 6
> 7 7 2
> 8 8 5
> 9 9 7
>
> I would like to obtain this:
>
>   A B
> 1 2 2
> 2 4 6
> 3 7 2
> 4 8 5
> 5 9 7
>
 > x <- subset(mydata, B>0)
 > row.names(x) <- rank(x$A)
 > x
   A B
1 2 2
2 4 6
3 7 2
4 8 5
5 9 7
> or this
>
>   A B
>   2 2
>   4 6
>   7 2
>   8 5
>   9 7
>
I think you already got this using subset.  The row.names can be used 
to set the row names to whatever you want.

Sean