CSINTERP 1-D piecewise cubic spline interpolation of tabulated data and calculation of first and second derivatives. - CSINTERP 1-D piecewise cubic spline interpolation of tabulated data and calculation of first and second derivatives.

线性插值，拉格朗日插值，多项式插值，二次多项式插值-Piecewise-Linear Fit.C Quadratic Polynomial Fit.C Polynomial Fit.C Condition Number of Vandermonde Matrix Lagrange Interpolating Polynomials

Debugging can be used, Based on piecewise nonlinear weight value Pso algorithm, Three-phase photovoltaic inverter and network simulation.