Lagrange's Polynomial Interpolation

Interpolates a scalar or vector yp = f(xp) with given x and y = f(x) vectors and xp query

Lagrange's Polynomial Interpolation based on weighted factors or Lagrange polynomials with sum = 1.

Example data:

x = [1 4 6 5]; % x vector

y = log(x); % y = f(x) vector

xp = 2 or xp = [2 3]; % x point(s) (scalar or vector) query

Use:

yp = Lagrangeinterp(x,y,xp)

to calculate

yp = f(x point) point(s) (scalar or vector)

[~,L] = Lagrangeinterp(x,y,xp)

to output the Lagrange polynomial cell array