Compute polynomial fitting between vectors 'x' and 'y'
Updated 15 May 2017

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[Coeffs, yhat, Residuals] = getPolyFit(x,y,n)

Compute polynomial fitting between vectors 'x' and 'y', and return the coefficients of the n-th order polynomial
used to fit the data, the fitting polynomial function (yhat), and the residuals. If the residuals exhibit "non-random" patterns, it
is an indication that the fit is not so good. To check them: bar(x,Residuals), xlabel('x'), ylabel('ŷ - y')
Note: the function ignores non-finite values(-Inf,Inf,NaN).


x : independent variable (column vector)
y : dependent variable I want to estimate (column vector)
n : order of the polynomial I use to fit


Coeffs : Coefficients of the best-fitting line
yhat : fitting polynomial function
Residuals : difference between observations predicted by the best fit and the real ones

Cite As

Ruggero G. Bettinardi (2024). getPolyFit(x,y,n) (, MATLAB Central File Exchange. Retrieved .

MATLAB Release Compatibility
Created with R2009a
Compatible with any release
Platform Compatibility
Windows macOS Linux
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