Re: matrix library ?

From: walter_at_[hidden]
Date: 2001-03-12 15:22:49

Hello,

Ronald Garcia wrote:

> There have actually been some proposals for such a library (there's 
an 
> old boost thread headed by Giovanni Ballestri at the end of last
> year).  I've been using ideas presented in his work and the 
discussion 
> that evolved around it to develop a library with very similar 
intent.

You are not alone ;-). We are currently developing a matrix library 
targeted mainly to implement classical numerical procedures the 
object oriented way.

One important question at the beginning was, whether we should try to 
support rank-n tensors like Blitz++ and POOMA. We decided not to.

> It hasn't yet proceeded to the point where I'm ready to propose it 
to
> boost, but I am definitely interested in conversation about the 
topic.

I currently see the following points to discuss when developing a 
matrix library:

- support for mathematical notation
As Toon Knapen mentioned, one should be able to write expressions 
with vectors and matrices in a form like y = A * x + b.

- efficiency
Next point is, that a matrix library has to compare with existing 
libraries wrt performance. So first one has no other option than to 
support expression templates. This eventually involves the need to 
incorporate a meta meta method like PETE to generate templates in C++!
But this does not seem to be the whole story. As far as I understand 
Todd Veldhuizen's Blitz++, one has to implement very clever 
evaluation kernels to get the most out of the box.

- functionality
We restricted our interest to support BLAS like functionality. But 
who knows, what else one can do with matrices and vectors...

-compatibility
This is an interesting question: should a boost matrix library run 
under MSVC for example?

Kind regards

J. Walter