Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Fixed Point iteration using matlab, whats wrong with my code?

  1. Mar 29, 2010 #1
    Fixed Point iteration using matlab, whats wrong with my code??

    1. The problem statement, all variables and given/known data
    We are suppose to use MatLab to make a program using the fixed point iteration to find the root of an equation.
    I just can't figure out what I'm doing wrong here...

    I'm pretty sure a while loop is the appropriate measure to use, but how should I go about plugging in g(x) which is the modified form of the original equation..
    2. Relevant equations



    3. The attempt at a solution

    %finds the approximate root using fixed point iteration
    %input: inline function g(x)
    %guess point x0
    %max error (err_max)
    %number of iterations (n)
    %output: x is the approx. root
    %k is the number of iterations carried out

    function root= fixed_point(g,x0,n,err_max)
    i=1;
    x(1)=g(x0);
    while i<=n
    x(i+1)=g(x(i));
    if abs((x(i+1)-x(i))/(x(i+1)) < err_max
    disp('Converges after k iterations')
    k=i;
    disp('The root to the equation is')
    x(i+1)
    return
    end
    i=i+1;
    end
     
  2. jcsd
  3. Mar 30, 2010 #2

    CEL

    User Avatar

    Re: Fixed Point iteration using matlab, whats wrong with my code??

    What kind of error are you getting?
     
  4. Mar 31, 2010 #3
    Re: Fixed Point iteration using matlab, whats wrong with my code??

    Could you comment your code? I can't quite figure out how this is supposed to perform fixed point iteration.
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook