[R] Vector indices

[Berton Gunter]

As you apparently haven't received any answer yet ...

Assuming your "table" is a data frame (str() will tell you), I believe you
are confusing the row names with indices. Please read the docs on data frame
for details (?data.frame). Row names are character strings that can be
indexed as such:

> test<-data.frame(x=1:4,y=letters[1:4])
> row.names(test)
[1] "1" "2" "3" "4"

> test
  x y
1 1 a
2 2 b
3 3 c
4 4 d

> test[2,]
  x y
2 2 b

> test['2',]
  x y
2 2 b

> test[2,1]<-NA
> test
   x y
1  1 a
2 NA b
3  3 c
4  4 d

> test2<-na.omit(test)
> test2
  x y
1 1 a
3 3 c
4 4 d

> test2[2,]
  x y
3 3 c

> test2['2',]
    x    y
NA NA <NA>

> test2['3',]
  x y
3 3 c


-- 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 Werner 
> Wernersen
> Sent: Tuesday, January 17, 2006 10:23 AM
> To: r-help at stat.math.ethz.ch
> Subject: [R] Vector indices
> 
> Hi,
>   
>   I am despairing of getting the indices for a vector:
>   First, I have a table from which I kick out a number of 
> rows with  na.omit. Next, I use this table for clustering 
> with kmeans and  cl$cluster contains my clusters. The 
> cl$cluster is a vector which still  contains my original 
> indices from the very beginning, a kind of like an  
> "associative" array. But how can I get a list of only these 
> indices?  When I use which() on the data it returns new 
> indices starting from 1  to N together with the "old" indices 
> but the "old" ones remain  unaccessible. 
>   
>   It would be great if someone could give me a hand with that.
>   
>   Thanks,
>     Werner
>   
> 
> 		
> ---------------------------------
> 
> 
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