You are right! With the spots in subsequent frames, the plot is exactly what I am looking for.
Unfortunately it is not feasible to do my analysis for every frame.
My data is not amenable to automatic tracking with TrackMate, so all tracking is manual. I am not really tracking spots, but rather the growing tip of a polarly expanding cell (pollen tube). Each time series has a very large number of cells to be tracked, and the temporal resolution is relatively high. (For reference, each time series has 121 time points, and I can effectively track the cell tip movement/growth with 5-10 spots)
Is there any way to have TrackMate to use the average velocity between two spots for all time points between those spots in order to produce this type of plot without spots in all frames?
Alternatively, is there a way to interpolate spots linearly between those that I have already placed so that there can, in fact be spots on all frames.