http://www.perlmonks.org?node_id=919242


in reply to Cartesian co-ordinate rotation around an Axis

$angle = 9.4; $translation = 0.4; $coefl1 = 1-cos($angle); $coefl2 = sin($angle);

$angle looks to be measured in degrees, whereas, cos, sin etc use radians.

</guess>