Hi everyone I was hoping someone could help with a problem I’m having. I am often given large amounts of X & Y data which relate to the edges of highways. Sometimes they are just a hand full approx 20 and other times there are approx 400. I use the data to find arcs that best fit the x & y data which is then used to calculate various other aspects of the highway (which I wont bore you with). My question is this; does anyone know of any calculators (online/excel/etc) that is available where by I can copy and paste in large rows of X&Y data and then the calculator then produces the arc of best fit i.e. the calculator should return the XY coordinates of the center of the circle and its radius. I am not that fussed as to how the arc of best fit is calculated i.e. may or may not use least squares, I just need something that is able to handle large rows of XY data. Can anyone help?