Simulate Ronchigrams on the fly using WebAssembly (Fast) or Javascript (Slow). See it in action at http://ronchigram.com WebAssembly mode uses KissFFT (https://github.com/mborgerding/kissfft) and JS mode uses mrquincle's JS FFT (https://gist.github.com/mrquincle/b11fff96209c9d1396b0) and math.js (https://github.com/josdejong/mathjs)