Re: Symmetric Matrices: time and space efficient represenation

[JuanPi]

On Fri, Feb 19, 2016 at 4:50 PM, Nir Krakauer <address@hidden> wrote:
> There is a function vech to store symmetric matrices in a space-efficient
> way. I don't know if this form can be used directly for operations with the
> matrices.
>
> https://www.gnu.org/software/octave/doc/interpreter/Rearranging-Matrices.html#XREFvech

Thanks Nir, yes, vech and unvec are used in the mechanics package to
do this, but it isn't optiomized so speed gains are minimal.
In a way it is quite easy to do symm. matrix-vector in Octave because
is an index problem and then a re-arrange, but I wanted ot chek if
somebody already implemented it. It seems the Eigen3 library has it.

-- 
JuanPi Carbajal
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