Good Morning Lorenzo,
I had a look at ?sort and it said "For ordering along more than one
variable, e.g., for sorting data frames, see 'order'." So I had a look
at ?order... and popped down to the examples and it talks about
ordering a dataframe - not the clearest of examples, but hey :-)
Sometimes the obvious is the hardest to see :-)
cheers!
Sean
On 16/11/05, L.Isella <L.Isella at myrealbox.com> wrote:
Dear All,
I have a long array (say 2xN, with N of the order of 10^5 at least) made
up of couples of numerical values.
I would like to sort these N couples in increasing order of the value of
the numbers in the lower row.
It is very easy to use sort() to take care of the sorting of the lower
row, but then I also have to sort the upper row so that the values of
each couple still match.
I did it using a double loop, but for large N this is very slow.
This is really a bottleneck in my code...
Any suggestions?
Regards
Lorenzo