[GAP Forum] Re: sine cosine decomposition

[Stefan Kohl]

Dear Forum,

sazzad at pdx.edu wrote:

> Is there anyone can decompose a 9X9 matrics to its sine cosine decomposition or
> let me give some hints in this regards in GAP.

I am not aware of a generally used term `sine cosine decomposition'
of matrices over whatever ring or field. Thus I think it is necessary
that you define this term before anyone can answer your question.

In case that you in fact rather want to compute singular value
decompositions of matices over the reals:

GAP as a system for computational discrete algebra does not provide
significant support for numerical computations with floating point
numbers, thus for doing these likely the only sensible recommendation
is to use another computer algebra system.

However you may have noticed that with the last update, some
undocumented *rudimentary* support for floating point numbers has
been added. If a significant number of users requests this, it is
conceivable that in later versions of GAP this will be improved
and documented, but at this point, nothing can be promised in this
respect.

Best regards,

     Stefan Kohl