[eigen] Eigen appears to rock.

["Thomas Vaughan" <tevaughan@xxxxxxxxx>]

I've been looking for a high-performance C++ class library that supports three-dimensional vectors, cross-products, rotations, etc.  I've long been using a simple-minded library that I wrote for myself, but performance has lately become a concern for me.  Over the past few days I've tried out tvmet and boost::numeric::ublas.  Not being satisfied with those, I started writing my own small library to do just what I want.  After all, implementing a template _expression_ is somewhat fun, and using the curiously recurring template pattern to avoid virtual functions is a neat trick.

Then I stumbled across eigen.

Amazing.

I just spent an hour or so reading through your API.

So far as what I need, the only thing that seems not already built in is the idea of a coordinate system (which includes both a basis and an origin) and the idea of a point (which transforms differently from a vector).  Of course, this can be handled with four-dimensional matrices and vectors as in OpenGL.  Maybe point-transform stuff is already in the geometry module, though I didn't see it.  Anyway, eigen looks so good that I thought that I would join the mailing list.  I'm sure to have questions once I start using it.

--
Thomas E. Vaughan

There are only two kinds of people; those who accept dogma and know it, and those who accept dogma and don't know it. - G.K. Chesterton