mrdoob/three.js — pull request #5595 by dmarcos (2014-11-09 08:55:56+00:00)
Title: Adds method to calculate the quaternion rotation angle

The two last unit tests don't pass because of floating point numbers precision. The formula works as expected.

The input angle is:
0.7853981633974483
The function output:
0.7853981633974484

Is there any specific way to handle these issues in threejs? Is it fare to truncate the results and discard some of the least significant decimal positions?