Re: [OctDev] FW: Cell array support

[Paul K. <pki...@ki...>]

I collected some patches in matcompat.  I don't know if it was worth the
trouble though.  I suppose it wouldn't hurt to create a new top level
directory /patches, just so long as nothing in main depends upon them.

	- Paul

On Tue, May 16, 2000 at 10:46:23PM -0400, Julian A. de Marchi, Ph.D wrote:
> I've been watching patches & usage tips float past it seems forever now.
> Do y'all not fancy we could compile these @SF in a way that's easier to
> use than troving through the octave.org mailing list archives?
> 
> Another unsolicited, obvious, back-seat remark from
> joolean
> 
> 
> -----Original Message-----
> From: oct...@be...
> [mailto:oct...@be...]On Behalf Of Jianming
> Sent: Thursday, May 17, 2001 6:47 AM
> To: Paul Kienzle; octave-sources
> Cc: John W. Eaton
> Subject: Re: Cell array support
> 
> 
> Hi,
>     Attached are the new patches for cell array support with octave
> (2.1.34). After experimenting with various implementations, I've taken most
> of your advices regarding the following:
>     1. Using () to access cell elements should not narrow down to the base
> type automatically. This will reduce confusion. I.E, narrowing conversion is
> removed.
>     2. Using ASSIGNANYOP in op-cell.cc
> 
>     Attached also is a sample session with the patch. Some comments on the
> (incomplete) patch:
> 
>     1. Some features with Paul mentioned in the previous email are missing:
>         a) {} producing multi-valued output
>         b) {} receive multi-valued output,
>         c) splice cell arrays into an argument list à la Matlab:
>     2. As shown in the sample session, assigning cell elements to an
> undefined indexed variable will give an error. To overcome this, cell(0,0)
> must be used first to "declare" the variable as a cell. There is no problem
> assigning cell elements to an undefined variable in it's entirety though.
>     3. Increasing the size of a cell array will not give unassigned elements
> as empty matrices as Matlab does. Instead, the undefined elements will have
> undefined type until assigned a value.
>     4. Removing elements from a cell is done using {} instead of []. This is
> simpler to implement. In fact, there is no need for any code for this. If we
> want to use [], I believe we have to delibrately check the type of the left
> hand side first. I don't really like this hack.
> 
>     Any comments, improvements are welcomed. Thanks Paul for your comments
> in the previous emails. I hope this gets into 2.1.35 together with some of
> your patches for cell functions.
> 
> Regards,
> Jianming







> octave:1> A(1,1) = {[1 4 3; 0 5 8; 7 2 9]};
> error: operator =: no conversion for assignment of `cell' to indexed `<unknown type>'
> error: evaluating assignment expression near line 1, column 8
> octave:1> A{1,1} = [1 4 3; 0 5 8; 7 2 9];
> error: A(I, J) = X: X must be a scalar or the number of elements in I must
> error: match the number of rows in X and the number of elements in J must
> error: match the number of columns in X
> error: evaluating assignment expression near line 1, column 8
> octave:1> A=cell(0,0);
> octave:2> A(1,1) = {[1 4 3; 0 5 8; 7 2 9]};
> octave:3> A{1,2} = 'Anne Smith'
> A =
> 
> {[1,1] =
> 
>   1  4  3
>   0  5  8
>   7  2  9
> 
> [1,2] = Anne Smith
> }
> 
> octave:4> A{2,2} = -pi:pi/10:pi
> A =
> 
> {[1,1] =
> 
>   1  4  3
>   0  5  8
>   7  2  9
> 
> [2,1] =
> 
> error: octave_base_value::print (): wrong type argument `<unknown type>'
> 
> [1,2] = Anne Smith
> [2,2] =
> 
>  Columns 1 through 8:
> 
>   -3.1416  -2.8274  -2.5133  -2.1991  -1.8850  -1.5708  -1.2566  -0.9425
> 
> 
>  Columns 9 through 16:
> 
>   -0.6283  -0.3142   0.0000   0.3142   0.6283   0.9425   1.2566   1.5708
> 
> 
>  Columns 17 through 21:
> 
>    1.8850   2.1991   2.5133   2.8274   3.1416
> 
> }
> 
> octave:5> C = {[1 2], [3 4]; [5 6], [7 8]}
> C =
> 
> {[1,1] =
> 
>   1  2
> 
> [2,1] =
> 
>   5  6
> 
> [1,2] =
> 
>   3  4
> 
> [2,2] =
> 
>   7  8
> 
> }
> 
> octave:6> C=A{1,1}
> C =
> 
>   1  4  3
>   0  5  8
>   7  2  9
> 
> octave:7> d=A{1,1}(2,2)
> d = 5
> 
> octave:8> A(1,:)
> ans =
> 
> {[1,1] =
> 
>   1  4  3
>   0  5  8
>   7  2  9
> 
> [1,2] = Anne Smith
> }
> 
> octave:9> A(2,:)=[]
> A =
> 
> {[1,1] =
> 
>   1  4  3
>   0  5  8
>   7  2  9
> 
> [2,1] = [](0x0)
> [1,2] = Anne Smith
> [2,2] = [](0x0)
> }
> 
> octave:10> A(2,:)={}
> A =
> 
> {[1,1] =
> 
>   1  4  3
>   0  5  8
>   7  2  9
> 
> [1,2] = Anne Smith
> }