Notes on Lagrange Interpolating Polynomials

(eli.thegreenplace.net)

15 points | by ibobev 1 hour ago

3 comments

  • commandersaki 47 minutes ago
    In the Polynomial Interpolation Theorem, you have r(x) = p(x) - r(x), but I think it should be q(x) = p(x) - r(x).
    • eliben 18 minutes ago
      Fixed, thank you! (it's actually r(x)=p(x)-q(x))

      (proof-reading through HN is a mildly embarrassing process, sorry about that! I do go over these posts and proof-read them several times myself before publishing)

  • hdrz 1 hour ago
    The Lagrange polynomials form the normal basis of most Finite Elements Method (FEM) software. There are other polynomials which are used as well, but these are the workhorse of most solvers.
  • wolfi1 1 hour ago
    the last matrix before the appendix is not the identity matrix, right now the matrix is: \begin{bmatrix} 1 & 0 & 0 & \dots & 0\\ 1 & 0 & 0 & \dots & 0\\ 1 & 0 & 0 & \dots & 0\\ \vdots & \vdots & \vdots & \ddots &\vdots \\ 1 & 0 & 0 & \dots & 1 \end{bmatrix}
    • eliben 1 hour ago
      Thanks for noticing, I'll fix it shortly