From: Tom Forsyth <tom.forsyth@bl...>  20040113 17:08:46

None of those change at all, except (1), where it will of course be "clockwise". Physics doesn't know or care what handedness your coordinate system is (except for a few funky little quantum effects). The only reasons "anticlockwise" changes to "clockwise" is because our definition of those terms does not change with the handedness. If you instead talked about "the spin along the z axis from +ve x towards +ve y", then again, nothing changes. TomF. > Original Message > From: gdalgorithmslistadmin@... > [mailto:gdalgorithmslistadmin@...] On > Behalf Of Bob Dowland > Sent: 13 January 2004 16:39 > To: gdalgorithmslist@... > Subject: [Algorithms] dynamics in lefthanded coordinate frames > > > A maths/dynamics question really for anyone who has tried > doing rigid body dynamics in a left handed world. I'm > wondering what or if there is a "usual" way to treat vector > xproducts / Coriolis / and so on in a left handed coordinate system. > > For eg., in no particluar order, a RHS has: > > 1 angles increase anticlockwise > > 2 e_i x e_j = e_k, for (i,j,k) any +ve perm of (1,2,3) > and e_i,j,k the usual unit direction vectors > > 3 Rdot = (omega*)R, ie epsilon_ijk.omega_j (R the > orientation of the body frame, omega the angular velocity > vector, epsilon_ijk the alternating tensor) > > 4 xdot_world = xdot_body + Cross(omega, x  cm_body) > > What happens to these in a LHS system to cope with > computation of angular quantities? > > Bob. 