Re: What is the expected behaviour of resize of NDArrays?

[David Bateman]

Ok then I'd suggest the attached patch instead. It seems to me that
there were quite a few problems with resize_no_fill and
resize_and_fill, that appeared after my previous patch. The attached
patch addresses these also. I also attach a test oct-file that can be
called like

 a = rand(2,2), b = dummy(a,ones(4,2),1)

or

 a = rand(2,2), b = dummy(a,ones([4,2]))

to show the behaviour of the resize functions.

Regards
D.


According to John W. Eaton <address@hidden> (on 04/20/04):
> On 20-Apr-2004, David Bateman <address@hidden> wrote:
> 
> | I have a problem that causes fft([1,2]',1) to crash for which a patch
> | is attached. However, while checking into this problem I identified a
> | strange difference in behaviour of resize_no_fill and resize_and_fill
> | in Array.cc. The code
> | 
> | dim_vector dv;
> | NDArray a;
> | ...
> | a.resize (dv);
> | 
> | Causes the random data to be placed at the end of a considered as a 
> | single index if dv is larger than a.dims() is some dimension. Whilst,
> | if dv is smaller than a.dims() is some dimension then it cut from the
> | end. This means that a = [1, 3; 2, 4]; when resized to [1,2] becomes
> | [1, 2] !!!
> | 
> | This is different than the behaviour for a.resize(dv, fill_value), which
> | respects the dimensioning of the previous array.
> 
> I think they should both do the same thing except that the _no_fill
> version should leave any new elements outside the bounds of the
> original array undefined.  So it looks like there is a bug in the
> current version of resize_no_fill.
> 
> jwe

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David Bateman                                address@hidden
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dummy.cc
Description: Text document

patch.resize2
Description: Text document