Daryle Walker said: (by the date of Wed, 21 Jun 2006 15:49:22 -0400)
On 6/19/06 12:03 PM, "Geoffrey Irving" <irving@cs.stanford.edu> wrote:
On Mon, Jun 19, 2006 at 09:43:45AM -0600, Dave Steffen wrote: [SNIP]
It seems to me that building operations for vectors-with-units and matrices-with-units is a duplication of effort. If the PQS library is as easy to use as [ it should be | we think it is ] then incorporating units into UBLAS should be both easy and a good exercise.
Small vectors and transforms require somewhat different interfaces than large vectors. For example, uBLAS does not have cross products, normalization, quaternions, exponential maps from vectors to quaternions, etc. [TRUNCATE]
But we have a quaternion library too....
yes, there is Boost.Quaternion library, but it is not suitable for working with geomnetry. Only math stuff. Several functions are missing, for example: from_rotation_matrix (builds a quaternion) from_axis_angle (builds a uaternion) to_euler_angle operator* (quaternion,vector) (rotates a vector) and a few others. I have investigated this library a bit, and the author has done some work in this direction, but finally gave up, because the only linear algebra library is Boost.Ublas.Numerics which has a bit unsuitable vector type (mainly because it is designed as a library for big vectors/matrices, not small vectors/matrices). There were problems on the interface between Boost.Quaternin and speed issues. so currently Boost.Quaternion is unusable for our purposes here. I hope that this will change once Dave's linear algebra library will be introduced... -- Janek Kozicki |