Re: next problem

[Paul Kienzle]

On Dec 22, 2003, at 10:53 PM, Quentin Spencer wrote:

> Rich Drewes wrote:
>
> > On Mon, 22 Dec 2003, Przemek Klosowski wrote:
> >
> >
> > > Can anyone explain to me why do I need the transpose, i.e. why, in
> > > Matlab, y(:,:,:,:)=[x, x, x, x] and y=[x, x, x, x] are different?
> >
> > I oversimplified my example problem.  The real line I was having 
> > trouble
> > converting from Matlab looked more like this:
> >
> > octave:3> F=[1,2,3; 4,5,6; 7,8,9]
> > octave:4> g(:,:,1,1)=F
> > error: invalid number of indices (4) for indexed assignment
> > error: assignment failed, or no method for `<unknown type> = matrix'
> > error: evaluating assignment expression near line 4, column 11
> >
> > The problem seems to be that Octave can't deal with (for example)
> > assigning 2 dimensions of a 4 dimensional array.  Matlab can, and of
> > course this idiom is all over the program I am trying to port.  Can 
> > you
> > suggest a convenient way of dealing with the issue of assigning 
> > certain
> > dimensions of a higher-dimensional array?  I can see elaborate ways of
> > working around this, but a conveniently similar idiom would make 
> > porting
> > much easier.
> As far as I can tell this isn't implemented yet. I ran into the same 
> thing a couple of days ago, and sent a bug report to the bug-octave 
> list. Actually, I found two bugs at the same time, because I also 
> discovered that the statement a(:,:,1)=ones(1,1,2) crashes octave. 
> Multidimensional array support has been added to octave only since 
> 2.1.51, so bugs are still being worked out (all of the ones that 
> affected my Matlab scripts are fixed in the CVS sources now). This may 
> be fixed by the next release, so if you're not in a hurry, I'd say 
> don't worry about rewriting your code yet.

However, you are likely going to get there faster if you contribute in
some way, such as documentation patches or test scripts.  See the
list of available tests in cvs/octave/test/octave.test --- I don't see 
any
N-D tests there, but I haven't looked very hard.

Paul Kienzle
address@hidden



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