Least Square Method, Curve Fitting, Python, Residual, Data.
φ1(xi) + β2 * φ2(xi) + … + βn * φn(xi) where: β0, β1, …, βn are the unknown parameters we want to estimate. φ1(xᵢ), φ2(xᵢ), …, φn(xᵢ) are functions of the input variable xᵢ. These functions can be simple polynomials of xi or any other relevant functions. The goal of the least squares method is to