"y \= scalar" fails

[Jaroslav Hajek]

On Mon, Mar 3, 2008 at 1:42 PM, Rolf Fabian <Rolf.Fabian at gmx.de> wrote:
>
>
>  Jaroslav Hajek-2 wrote:
>  >
>  > this seems 100% correct.
>  > y \= c means y = y \ c = inv(y) * c,
>  >
>
>  Thanks for explaining me, what a backslash
>  division is supposed to do.
>
>

Unfortunately, I didn't. The inv(y)*c thinkg was a mistake; it does
not work that way.
y \= c is indeed equivalent to y = y\c, the rest is not true.
"Supposed to" is the problem here. Supposed by whom?

>
>
>  > but size(y,2) != size(c,1).
>  >
>
>  Unfortunately you forgot to line out the
>  problem which Octave has to multiply a
>  square matrix by a scalar value. i.e.
>  evaluating "inv(y) * c" .
>  Is "inv(y) * c" not anymore identical
>  to "inv(y) .* c" or did I miss something?
>
>

No, as I confessed above, this is true. The problem is that matrix
left division A \ B is not
defined as inv(A) * B (for one thing, A does not have to be square.)


>
>
>  > Matlab gripes as well here.
>  >
>
> > RNDr. Jaroslav Hajek
>  > computing expert
>  > Aeronautical Research and Test Institute (VZLU)
>  > Prague, Czech Republic
>  > url: www.highegg.matfyz.cz
>  >
>
>  There seem to be many features of ML which
>  are weird, strange or obscure. They do not
>  necessarily have to be merged into Octave
>  without critically reflecting them.
>
>
>
>  -----
>  Rolf Fabian
>  <r dot fabian at jacobs-university dot de>
>
>  --
>  View this message in context: http://www.nabble.com/%22y-%5C%3D-scalar%22-fails-tp15799910p15802174.html
>
>
> Sent from the Octave - Bugs mailing list archive at Nabble.com.
>
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-- 
RNDr. Jaroslav Hajek
computing expert
Aeronautical Research and Test Institute (VZLU)
Prague, Czech Republic
url: www.highegg.matfyz.cz