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Subject: Re: fix point iteration
Date: Sat, 25 Apr 2009 19:11:01 +0000 (UTC)
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"Yi" <hvachy@163.com> wrote in message <gsvhnt$gmt$1@fred.mathworks.com>...
> I want to plot a curve, x is my independent value, and y is the dependent value. 
> But I have
> y = f1(a,b,x)
> a = g1(a,b,x)
> b = g2(a,b,x)
> I want to assume the x value in a reasonable interval and then use fix point iteration to solve a and b first, using function a and b. Then drive these a and b and x(assumption) into y and then plot the curve. 
> I don't know how to solve a and b. Which command should I use? 

  Fixed point iteration is a very general concept for solving equations.  It is necessary to choose an appropriate formula/method for carrying out the iteration, as for example the Newton-Raphson method or Halley's method.  In your case you need a two-variable method.  See the Wikipedia article at:

 http://en.wikipedia.org/wiki/Fixed_point_iteration

Roger Stafford