interesting feature

From: Svetlana Eden

Hi, everybody.
This was an interesting discussion last time and it helped me a lot.

Could you please have a look at some feature and tell me
why it was designed this way
(my questions are under #########)

x = c(1, 10)
y = c(99, 55)
d <- data.frame(x = x, y = y)
d

   x  y
1  1 99
2 10 55

add <- data.frame(x = 14, y = 99)
add

   x  y
1 14 99

d <- rbind(d, add)
d

    x  y
1   1 99
2  10 55
11 14 99
######### it would be more natural to index the rows: 1,2,3 instead of
#1,2,11  ?!

d[3,1]

[1] 14

d[11,1]

[1] NA
######### especially if index '11' is not functioning...

d[1,11]

d[11,1] <- 1
dim(d)

d

add1 <- data.frame(x = 10, y = 87)
d <- rbind(d, add)

######### now I would think that the next index should be 21, BUT:

d

    x  y
1   1 99
2  10 55
11 14 99
12 10 87
######### so what is the intuition of such indexing?

-- 
Svetlana Eden        Biostatistician II            School of Medicine
                     Department of Biostatistics   Vanderbilt 
University