Activity for Fred Wamsleyâ€
| Type | On... | Excerpt | Status | Date |
|---|---|---|---|---|
| Edit | Post #286472 | Initial revision | — | almost 2 years ago |
| Question | — |
Are vectrices useful for calculations as opposed to formalism? The context here is calculations about satellite attitude control and motion. There is a frequent need to convert between reference frames, and a vectrix is a clever notation to assist. The fundamental idea is to represent a frame of reference by a 3x1 matrix in which the elements are not scalars... (more) |
— | almost 2 years ago |
| Edit | Post #286166 | Initial revision | — | about 2 years ago |
| Question | — |
Complex numbers in 2D, quaternions in 4D, why nothing in 3D? I'm just trying to understand why quaternions are necessary. If I understand right, first off please check me on this, Hamilton kept trying to find ways to multiply triplets and found something satisfactory only when he escalated to four dimensions. So game coders and spacecraft engineers extend ... (more) |
— | about 2 years ago |
| Comment | Post #285984 |
As to why they're not commutative, think of them in terms of their application to describe rotation. Grab something from a set of dice, a cube with unique markers on each face. Make a note of which side is facing you, then rotate it around the x axis and then around the y axis. Make a note of the sid... (more) |
— | about 2 years ago |