Typical problems in this class include polynomial interpolation Φ(x;a0,,an) = a0 + a1x + a2x2 + ··· + anxn, as well as trigonometric interpolation Φ(x;a0,,an) = a0 + a1exi + a2e2xi + ··· + anenxi (i2 = −1).
Interpolation with python functions
The interpolant polynomial can be computed with numpy function polyfit if we choose as polynomial degree the number of the nodes minus one.
The output is the coefficients of the polynomial, from an to a0.
To apply polynomial interpolation in Excel, you can use the LINEST function, which is designed for linear and polynomial regressions.
The LINEST function can be used to determine the coefficients of a polynomial that fits your data.