data.frame indexing

Dear R Community,     A simple problem (for some of you): I wish to  
index a
data.frame by all elements NOT in my index
E.g.:

a<-as.data.frame(matrix(rnorm(100),nrow=10,ncol=10))
b<-which(a$V1>0.8)
b

[1]  1  4  6 10

a_indexb<-a[b,]
a_notIndexB<-a[!b,]
nrow(a_notIndexB)

[1] 0

Indexing a on b is not a problem (a_indexb), but how can do get  
only the
elements left if I take out the elements indexed with b?

Hi,

I think one of the most wonderfully magic things about R is that it  
can use a logical array to index other things (like a data frame).   
You could use the extra step with which, but in your case you can  
bypass that step.  Here is a simple example...

 > a <- data.frame(V1 = seq(-5,5), V2 = seq(-5,5))
 > a
    V1 V2
1  -5 -5
2  -4 -4
3  -3 -3
4  -2 -2
5  -1 -1
6   0  0
7   1  1
8   2  2
9   3  3
10  4  4
11  5  5
 > b <- a$V1 > 0
 > b
  [1] FALSE FALSE FALSE FALSE FALSE FALSE  TRUE  TRUE  TRUE  TRUE  TRUE
 > a[b,]
    V1 V2
7   1  1
8   2  2
9   3  3
10  4  4
11  5  5
 > a[!b,]
   V1 V2
1 -5 -5
2 -4 -4
3 -3 -3
4 -2 -2
5 -1 -1
6  0  0

Hope that helps!

Ben