I should probably be asking Excel's programmers, but I have been lucky in this forum lately; here is what I got going on: I have a data table composed of two variables: time and angular velocity of a particle around a centre point. Time is just 0.0, 0.1, 0.2 (in seconds) and so on. Angular velocity is given once every 0.1 second in Radians/second. The angular velocity generally decreases but there are small spikes going up and down. What I want to do is that I want to know when will the particle be in a position where it is on the right of (or 0 degrees in relation to) the centre. My calculus is mediocre, but I think what I need to do is to plot the angular velocity over time on a graph, and then add the area under the curve into blocks of 2π, at the edge of each block would be the point in time where the particle is in the desired position, but there isn't a simple function describing the motion of the particle that I can integrate (due to the spikes) and the data set is kind of big, so I am just wondering if there's any way to get those points in time easily.