You need to decide first what kind of function gives a good model for your (x,y) data. If the (x,y) data come from a polynomial, use POLYFIT. If they come from a more complicated function, use NLINFIT.
That's correct! POLYFIT is a function specifically designed for fitting polynomial curves to data.
POLYFIT returns the coefficients of the fitted polynomial. These coefficients can be used to create the equation of the polynomial curve, getaway shootout can then be used for various purposes such as prediction, interpolation, or smoothing.
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