Is there a way in Mathematica to find the local maxima of a set of points? I have a fairly fine data set, and I can clearly see several peaks in it that I would like to know the numerical value of (as in, the highest point- I don't need a spline approximation or anything too fancy like that). I have already smoothed the set, so I'd rather not fit polynomials if possible. Additionally, is there a way to find the expected zeros of a set? Let's say that I have two points in order, and somewhere between them the measured response value drops to negative. I know I can find this manually, but there are enough zeroes that I would prefer not to. I am not too picky regarding whether the guessed zero is based on a linear connection between the two points or some sort of exotic polynomial or spline. Thanks very much.