Re: sqrtm test failure

[Jussi Lehtola]

On Sat, 30 Jul 2011 22:10:01 -0500
Jordi Gutiérrez Hermoso <address@hidden> wrote:
> >> isnan(sqrtm ([0 1; 0 0]))
> > warning: sqrtm: matrix is singular, may not have a square root
> > ans =
> >
> >   0   1
> >   0   1
> 
> I wrote that test during the code sprint, because certain kinds of
> matrices should fail to produce a square root. Perhaps rewrite the
> test to use "any"? Or could the output be anything? Is there a way
> merely test that it produces a warning?

What do you mean by "fail to produce a square root"?

A non-symmetric matrix can easily be seen not to have a square root,
but taking the square root of a singular symmetric matrix should be
supported, since the operation can be seen to be well defined via the
SVD.
-- 
Jussi Lehtola
Fedora Project Contributor
address@hidden