Hmm, you're right of course. I was unconsciously assuming
that a single row/column matrix would be treated like a
vector. Is there something like vect_norm() that I'm missing?
Kostas
On 09/16/10 03:51 PM, Barton Willis wrote:
> The 1-norm is the largest column sum and the infinity norm the largest row sum; for example, see
>
> http://mathworld.wolfram.com/MatrixNorm.html
> http://en.wikipedia.org/wiki/Matrix_norm
>
> The column sums of matrix([a,b,c]) are |a|, |b|, and |c|. So
>
> (%i54) mat_norm(matrix([a,b,c]),1);
> (%o54) max(abs(a),abs(b),abs(c))
>
> The row sum of matrix([a,b,c]) is |a| + |b| + |c|. So
>
> (%i55) mat_norm(matrix([a,b,c]),inf);
> (%o55) abs(c)+abs(b)+abs(a)
>
> --Barton
>
> -----maxima-bounces at math.utexas.edu wrote: -----
>
> To: maxima<maxima at math.utexas.edu>
> From: Kostas Oikonomou<ko at research.att.com>
> Sent by: maxima-bounces at math.utexas.edu
> Date: 09/16/2010 02:14PM
> Subject: matrix norm (mat_norm) problem?
>
> Hi,
>
> It seems to me that the definitions of the 1-norm and the
> infinity-norm are switched in maxima 5.22.1:
>
> (%i1) m : matrix([a,b,c]);
> (%o1) [ a b c ]
> (%i2) [mat_norm(m,inf), mat_norm(m,1)];
> (%o2) [abs(c) + abs(b) + abs(a), max(abs(a), abs(b),
> abs(c))]
> (%i3)
>
> Kostas
> _______________________________________________
> Maxima mailing list
> Maxima at math.utexas.edu
> http://www.math.utexas.edu/mailman/listinfo/maxima