[GiNaC-devel] Find length of a vector

[Richard B. Kreckel]

Hi,

On 11/2/24 12:11 PM, Jan Rheinländer via GiNaC-devel wrote:
> trying to find the length of a vector by taking the square root of the 
> scalar product, I get this (in ginsh):
> 
>> v = [[a,b]];
> [[a,b]]
>  > r = sqrt(v * transpose(v));
> sqrt([[a,b]]*[[a],[b]])
>  > evalm(r);
> matrix::pow(): don't know how to handle exponent
> 
> The reason is that the scalar product evaluates to a matrix with a 
> single element, not to a numeric.

There are just matrix products evaluating to matrices. There is no 
special case for scalar products (apart from the quite special stuff in 
indexed.h).

> Is that intended?

Well, it's the way it is designed.  ;-)

   -richy.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: OpenPGP_signature.asc
Type: application/pgp-signature
Size: 840 bytes
Desc: OpenPGP digital signature
URL: <http://www.ginac.de/pipermail/ginac-devel/attachments/20241102/cd67c0a2/attachment.sig>