STACKOVERFLOW.com, 2013. How to map atan2() to degrees 0-360 [online]. Available from: https://stackoverflow.com/questions/1311049/how-to-map-atan2-to-degrees-0-360 [Accessed 26 May 2017]

The users in this stackoverflow thread offer many different solutions, however the posts by Fibbles and Liam George Betsworth were the most useful for understanding how to remap atan2 to a more useful range of angles. Initially it produces the angles 0 to 180, and 0 to -180. The solution using an if statement is the one I chose, and has worked effectively for the Y axis rotation. Since the VEX rotation function requires radians and not degrees, the angles produced are converted and easier to understand as 0 to 180, than 0 to PI.



YOUTUBE.COM, 2013. Rotation Matrix Direction [online]. Avalilable from: https://www.youtube.com/watch?v=GbhTCg0FCr4 [Accessed 26 May 2017]

This short video by Jamie King visually explains the how a rotation matrix effects a cube, but not the mathematics. Arrows and stick figure hands are drawn on top of the x, y, and z axis to explain how a right-handed coordinate system rotates an object. The video talks about opengl, however Houdini uses a right-handed coordinate system.



SIDEFX.COM, 2017 Houdini 16.0 VEX [online]. Avalilable from: http://www.sidefx.com/docs/houdini/vex/_index [Accessed 26 May 2017]

This page on VEX is part of the Houdini documentation, it describes how it is used and where. The language reference and list of specific context functions can be found here too.