[Rd] vector labels are not permuted properly in a call to sort() (R 2.1)
Greg Finak
finak at mcb.mcgill.ca
Tue Oct 4 19:36:25 CEST 2005
Not sure if this is the correct forum for this, but I've found what I
would consider to be a potentially serious bug to the unsuspecting user.
Given a numeric vector V with class labels in R, the following calls
1.
> sort(as.matrix(V))
and
2.
>as.matrix(sort(V))
produce different ouput. The vector is sorted properly in both cases,
but only 2. produces the correct labeling of the vector. The call to
1. produces a vector with incorrect labels (not sorted).
Code:
>X<-c("A","B","C","D","E","F","G","H")
>Y<-rev(1:8)
>names(Y)<-X
> Y
A B C D E F G H
8 7 6 5 4 3 2 1
> sort(as.matrix(Y))
[,1]
A 1
B 2
C 3
D 4
E 5
F 6
G 7
H 8
> as.matrix(sort(Y))
[,1]
H 1
G 2
F 3
E 4
D 5
C 6
B 7
A 8
Cheers,
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