I have in the past thought that quaternions would be a nice addition to J. They are very useful, for example, for expressing rotations of geometric models.
However, J of course needs its implementation to be generally correct and not just correct for some specific application. So I have been thinking of how to model J's primitives that would need to interpret quaternion values. This leads to questions such as: what does x^y mean when x and y are quaternions? Apparently, this is a hard problem: http://www.zipcon.net/~swhite/docs/math/quaternions/analysis.html I have been trying to find a definition of quaternion exponentials that that does not do something silly (like assume that quaternion multiplication is commutative). So far, I have not found anything I feel I could implement a J model for transcendental functions from. Also, x^y for quaternion x and quaternion y would often enough have an infinite set of valid results, which complicates things. So... does anyone have an good ideas about how to handle transcendental functions that work with quaternions? Thanks, -- Raul ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
