Glas List: Re: [glas] value type

From: Robert P. Goddard (Robert_Goddard_at_[hidden])
Date: 2005-10-03 14:20:59

Glas list,

In reply to Karl Meerbergen's request, please consider quaternions (e.g. 
boost::quaternion) for glas support as a value type. My interest is 
practical: Quaternions figure in differential equations describing the 
dynamics of rigid body rotations. Mathematically, they act like a bigger 
"complex" except that multiplication isn't commutative.

Octonians (e.g. boost::octonian) belong to the same mathematical family 
("division algebras"), so perhaps should be candidates. However, I don't 
know of a practical application for them, so their priority is much 
lower. Like maybe zero. Does anyone else know a scientific or 
engineering application for octonians?

Robert Goddard

glas-request_at_[hidden] wrote:

>Hello,
>
>We now have started the development of some functions for vectors since 
>a few weeks. All of them rely on the fact that the value_type's are 
>numerical value types (NumericValue concept). In the first document 
>about GLAS we supposed that vectors and matrices only contain numerical 
>values. I recall vague suggestions on the mailing list on expanding the 
>value_type to other than float, double, std::complex<float>, 
>std::complex<double>.
>
>Before continuing with any more new algorithms, it might be good to know 
>which other value_type's should be supported.
>
>I recall a demand for supporting vectors of matrices and matrices of 
>matrices. My opinion is that this should be another type of collection 
>where the value_type is still the value_type of the lowest level of 
>matrix in the nesting of matrices.
>
>Should we provide a bool value_type and corresponding functions !v, v || 
>w, v && w etc?
>
>Have a nice day,
>
>Karl
>
>  
>