This week's book giveaway is in the Mac OS forum. We're giving away four copies of a choice of "Take Control of Upgrading to Yosemite" or "Take Control of Automating Your Mac" and have Joe Kissell on-line! See this thread for details.
Strange, I thaught that % (= modulus computation) is only defined for integers. But experimenting shows that it works in Java too for floats and then you can get rounding errors, because not all floats can be expressed exactly in (internal) binary format. What is done looks like: 6.3f-Math.round(6.3f/2.1f)*2.1f mimicing 'real modulus' computation. So I would not use 'modulus' with floats.