Name

even_angles - generate a list of quasi-uniformly distributed Eulerian angles

Usage

angles = even_angles(delta, [ theta1, theta2, phi1, phi2, method, phiEqpsi, symmetry])

Input

delta
angular spacing of Eulerian angles
theta1
lower range of theta (optional, default = 0.0)
theta2
upper range of theta (optional, default = 90.0)
phi1
lower range of phi (optional, default = 0.0)
phi2
upper range of phi (optional, default = 359.99)
method
method of quasi-uniformly distributing Eulerian angles: 'P' Penczek '94 algorithm, theta angle is changing in steps of delta (default) or 'S' Saff hellical method
phiEqpsi
If this string is set to 'Minus' (default) then each of the Eulerian angles psi will be set to -phi. This results in neighboring projections having similar in-plane orientations. Otherwise, ('Zero') psi is set to zero.
symmetry

point group symmetry - the program will return angles for asymmetric unit, possibilities are cn, dn, tet, oct, ico (default c1). Currently, for icosahedral symmetry, the angles correspond to 5-fold symmetry axis placed on z-axis. Use list_syms to see the available symmetries.

Output

angles:: - a list of Eulerian angles stored as:

...

Reference

Author / Maintainer

Pawel A. Penczek and P. R. Baldwin

Keywords

category 1
UTILITIES

Files

utilities.py

Maturity

stable
works for most people, has been tested; test cases/examples available.

PRB checked (8/22/06) the Saff algorithm pretty carefully for large solid angles, but not for very small ones.

Bugs

None. It is perfect.

even_angles (last edited 2013-07-01 13:12:50 by localhost)