From bug-request at octave dot org Thu Apr  6 15:38:44 2006
Subject: bincoeff gives wrong results on bad input
From: "John W. Eaton" <jwe at bevo dot che dot wisc dot edu>
To: martin <martinxyz at gmx dot ch>
Cc: bug at octave dot org, martin@old.homeip.net
Date: Thu, 6 Apr 2006 16:38:39 -0400

On 22-Mar-2006, martin wrote:

| To: bug at octave dot org
| Cc: martin at old dot homeip dot net
| Subject: bincoeff gives wrong results on bad input
| 
| Bug report for Octave 2.1.72 configured for i486-pc-linux-gnu
| 
| Description:
| -----------
| 
| Bincoeff succeeds silently on buggy input.
| 
| Another note, nchoosek should perhaps work too, for matlab
| compatibility.
| 
| Repeat-By:
| ---------
| 
| octave:10> bincoeff(4, 55)
| ans = 0 # that is fine I guess
| octave:8> bincoeff(-4, 4)
| ans = 35 # I don't think it makes sense to give a result here?
| octave:7> bincoeff(-4, -1)
| ans = NaN # not sure about this one

So what should the results be?

I don't know what the correct thing to do is here, so someone who
knows will have to provide a patch.

jwe



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