logm, funm, sqrtm

[Tommy Guy]

Phillip wrote:

>FWIW, one of the authors of your literature ref provides a (basic) matrix
>functions toolbox under the GPL v. 3 license:
> http://www.maths.manchester.ac.uk/~higham/mftoolbox/

>Another (significantly more involved) one is on this web page:
> http://www.maths.manchester.ac.uk/~higham/NAMF/
>There's no mentioning of any license, only a note on the web page of the
>institution that supplied the grant for the research that led to this
>toolbox, that Intellectual Property is a responsibility of the researchers
>in question.

>Philip

There is a package available through Higham's lab.  I am new to Octave
hacking and I am not sure what, legally, we are allowed to do with
this code.  If we are allowed to adapt what we need for logarithms, we
could add that to the trunk.  Should someone contact him?

Regarding the development of a funm function like the one in the
competition, logm has a few peculiarities due to the fact that the
Taylor expansion is not globally convergent.  This suggests that while
funm would be a good idea, logm as a separate unit is also probably
necessary.

Tommy Guy