Lebesgue Constant (interpolation) - Definition

Definition

We fix the interpolation nodes x0, …, xn and an interval containing all the interpolation nodes. The process of interpolation maps the function f to a polynomial p. This defines a mapping X from the space C of all continuous functions on to itself. The map X is linear and it is a projection on the subspace Πn of polynomials of degree n or less.

The Lebesgue constant Λn(T) is defined as the operator norm of X. This definition requires us to specify a norm on C. The maximum norm is usually the most convenient.

Read more about this topic:  Lebesgue Constant (interpolation)

Famous quotes containing the word definition:

    “Scientific method is the way to truth, but it affords, even in
    principle, no unique definition of truth. Any so-called pragmatic
    definition of truth is doomed to failure equally.”
    —Willard Van Orman Quine (b. 1908)

    “... we all know the wag’s definition of a philanthropist: a man whose charity increases directly as the square of the distance.”
    —George Eliot [Mary Ann (or Marian)

    “The physicians say, they are not materialists; but they are:MSpirit is matter reduced to an extreme thinness: O so thin!—But the definition of spiritual should be, that which is its own evidence. What notions do they attach to love! what to religion! One would not willingly pronounce these words in their hearing, and give them the occasion to profane them.”
    —Ralph Waldo Emerson (1803–1882)