curvesmoothing

I have some 9000 points that are plotted on a graph: [ Full resolution ] Actually, the plot is not as smooth as I wanted it to be. Is there some way I can smoothen the graph to a required degree? Or some form of thresholding so that I can selectively smoothen out the parts that is too bumpy? I am not sure but can fast-fourier-transform help? A simple (ad hoc) way is to just take a weighted average (tunable by alpha ) at each point with its neighbors: data(2:n-1) = alpha*data(2:n-1) + (1-alpha)*0.5*(data(1:n-2)+data(3:n)) or some variation thereof. Yes, to be more sophisticated you can Fourier

I'm reading data from a device which measures distance. My sample rate is high so that I can measure large changes in distance (i.e. velocity) but this means that, when the velocity is low, the device delivers a number of measurements which are identical (due to the granularity of the device). This results in a 'stepped' curve. What I need to do is to smooth the curve in order to calculate the velocity. Following that I then need to calculate the acceleration. How to best go about this? (Sample rate up to 1000Hz, calculation rate of 10Hz would be ok. Using C# in VS2005) The wikipedia entry