  Single particle 3D imaging with ultrashort X-ray laser pulses is based on
collecting and combining the information content of 2D scattering patterns of
an object at different orientations. Typical sample-delivery schemes leave
little or no room for controlling the orientations. As such, the orientation
associated with a given snapshot should be estimated after the experiment. Here
we present an open-source code for the most rigorous technique having been
reported in this context. Some practical issues along with proposed solutions
are also discussed.
