Hello Barton,
It seems reasonable for transpose(transpose(m))
where m is a matrix to be equal to the original
matrix.
However:
(%i16) m1:zeromatrix(1,0);
(%o16) matrix([])
(%i17) m2:transpose(transpose(zeromatrix(1,0)));
(%o17) matrix()
(%i18) if m1 = m2 then true else false;
(%o18) false
Regards,
Dan
Barton Willis wrote:
> Dan,
>
> I'm not sure what you are trying to do, but I wonder
> if you can do what you want without appending size
> info to the car of a matrix.
>
> (%i1) m1 : matrix([],[]); <--- matrix with 2 rows and 0 cols
> (%o1) matrix([ ],[ ])
>
> (%i2) m2 : matrix([1],[2]);
> (%o2) matrix([1],[2])
> (%i3) addcol(m1,m2);
> (%o3) matrix([1],[2]) <--- this is OK
>
> (%i4) addcol(m2,m1); <--- I think this should work, but it doesn't
>
> Incompatible structure - ADDROW//ADDCOL
>
> (%i5) load(linalg)$ <--- my linalg code
>
> (%i6) matrix([m1,m2]); <--- a block matrix
> (%o6) matrix([matrix([ ],[ ]),matrix([1],[2])])
> (%i7) unblockmatrix(%);
> (%o7) matrix([1],[2]) <--- OK
>
> (%i8) matrix([m2,m1]); <--- try again
>
> (%o8) matrix([matrix([1],[2]),matrix([ ],[ ])])
> (%i9) unblockmatrix(%);
> Incompatible structure - ADDROW//ADDCOL <--- isn't this a addcol bug?
>
> And maybe we've been through this before, but why can't you
> find the matrix size without storing it?
>
> (%i12) length(m1);
> (%o12) 2
> (%i13) length(first(m1));
> (%o13) 0
>
> Barton
>
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