Hi, I am in an undergrad numerical analysis course. Our instructor lectured on some material not found in the book. Specifically, he talked about a way to check stability of finite differencing schemes (for PDE) by studying how each Fourier mode evolves in time. Then you can find an "amplification factor" which can tell you when the method is stable. Sorry if this is vague, but does it sound familiar to anyone? I would like to know the technical name for this process so I can do further research about it because I do not really understand at present. Also, if anyone knows of any books that cover it, I'd like to know their titles. Thanks in advance.