function handles & closures - porting from matlab

[John W. Eaton]

On 29-Jul-2009, Ian Rickard wrote:

| I'm currently trying to port a code base from matlab to octave.  It
| uses the following pattern extensively:
| 
| function fns = gen_poly_funs(n)
|     fns = arrayfun(@(n)(@(x)x.^n),0:n,'UniformOutput',false);
| end
| 
| As far as I can tell this pattern breaks in Octave, as there appears
| to be a single global value for n.  Is there an easy way to mimic
| matlab's behavior where the n is unique for each of the returned
| function handles?

What version of Octave are you using?

What result are you expecting?

Here is what I see when using Octave 3.2.0:

  octave3.2:1> function fns = gen_poly_funs(n)
  >     fns = arrayfun(@(n)(@(x)x.^n),0:n,'UniformOutput',false);
  > end
  octave3.2:2> gen_poly_funs (2)
  ans =

  {
    [1,1] =

  @(x) x .^ n

    [1,2] =

  @(x) x .^ n

    [1,3] =

  @(x) x .^ n

  }

Is that not correct?

In any case, if you think you've found a bug in Octave, then  please
send a complete bug report to the address@hidden list.  To find out
what information to include in your bug report so that it is useful,
please read http://www.octave.org/bugs.html.

jwe