多项式和非多项式曲线拟合，多项式拟合在matlab中可以使用polyfit函数求解多项式系数，通过polyval函数求解拟合多项式在某数据点处的值-Polynomial and non-polynomial curve fitting, polynomial fitting in matlab polyfit function can be used to solve polynomial coefficients, solve the value of a data point to fit a polynomial function by polyval