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Elliptic integrals

  1. Oct 20, 2011 #1
    I applied Gauss-lobatto method to solve elliptic integral in my problem. one of my parameters(distance) is infinity. in my problem the answer of elliptic integral at large distance should be zero but I can't get this result numerically. when distance goes to infinity, my program stopped working.
    I am looking for the resean and I guess this might be because the Gauss-lobatto method is not accurate for my problem.
    I used following code:

    N = max(3*round((N−1)/3),3) + 1; % Adjust N to the closest valid choice
    h = (b − a)/(N−1);
    d = (3/sqrt(5) − 1)*h/2;
    x = (a:h:b).'; x(2:3:N−2) = x(2:3:N−2) − d; x(3:3:N−1) = x(3:3:N−1) + d;
    w = ones(1,N); w(4:3:N−3) = 2; w([2:3:N−2,3:3:N−1]) = 5; w = w*h/4;
    I = w * f(x); % Approximately evaluate the integral

    please let me know if you have any idea.
  2. jcsd
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