the results of the SORT function differ from Scilab/Matlab for Complex Numbers
On 08/11/2012 4:42 PM, Cleber N.Borges wrote:
Ok, thanks. There are a simple mode for emulate this behaviour?
This should sort by modulus then argument (phase): x[order(Mod(x), Arg(x))] It does strange things if x happens to be real: > x <- (-5):5 > sort(x) [1] -5 -4 -3 -2 -1 0 1 2 3 4 5 > x[order(Mod(x), Arg(x))] [1] 0 1 -1 2 -2 3 -3 4 -4 5 -5 but that may be what you want. Duncan Murdoch
Cleber Em 08/11/2012 19:25, Thomas Lumley escreveu:
On Fri, Nov 9, 2012 at 10:02 AM, Cleber N.Borges <klebyn at yahoo.com.br
<mailto:klebyn at yahoo.com.br>> wrote:
Hello useRs,
The results of the SORT function differ from Scilab/Matlab for
Complex Numbers in my example.
This design is the desirable in R?
Well, it's deliberate and documented.
R sorts complex numbers by real part then by imaginary part. Matlab,
according to its documentation, sorts by modulus then phase.
There isn't a unique way to sort complex numbers, so you're going to
get differences. Personally, I think the R method is more
straightforward, since you don't need to decide and remember where the
branch cut goes on the phase coordinate.
-thomas
--
Thomas Lumley
Professor of Biostatistics
University of Auckland
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