Adk44: Created page with "= Introduction = In the angle-axis framework, rotations are described by a vector of rotation, while its magnitude is the angle of rotation. A good review on rotations in gene..."

2019-05-13T11:14:44Z

Created page with "= Introduction = In the angle-axis framework, rotations are described by a vector of rotation, while its magnitude is the angle of rotation. A good review on rotations in gene..."

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= Introduction =
In the angle-axis framework, rotations are described by a vector of rotation, while its magnitude is the angle of rotation. A good review on rotations in general can be found [http://www.mech.utah.edu/~brannon/public/rotation.pdf here].

Another useful resource is Dwaipayan and David's PCCP paper [http://pubs.rsc.org/en/Content/ArticleLanding/2009/CP/b818054g]. It tells you how to write down the first and second derivatives in angle-axis framework. Note, however, that there is a mistake in the formula for R_{kl} in the limit \theta = 0. This has been corrected both in GMIN and OPTIM implementations.

= Random rotations and takestep =
Be carefule with random rotations and takestep in the angle axis framework. Always use the functions rot_random_* and rot_takestep_aa. For an outline of the problem see [http://www-wales.ch.cam.ac.uk/vr274/files/uniform_rotations.pdf this talk].

= Normal modes =
Computation of normal modes in angle-axis framework: [http://www-wales.ch.cam.ac.uk/vr274/files/normalmodes.pdf talk]

Angle-axis framework - Revision history

Adk44: Created page with "= Introduction = In the angle-axis framework, rotations are described by a vector of rotation, while its magnitude is the angle of rotation. A good review on rotations in gene..."