36 lines
745 B
Matlab
36 lines
745 B
Matlab
function [N,x] = fixpoint (x0)
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% Function fixpoint
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% In: Start value
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% Out: number of iteration steps, vector of solution
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N=1;
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xCur = x0;
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xOld = x0;
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epsilon = 10^(-8);
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A = [3,4;1,6];
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function [y] = f(x)
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yTemp = (A - x(3)*eye(2))*[x(1);x(2)];
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lambda = x(1)^2+x(2)^2-1;
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y = [ yTemp ; lambda];
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end
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function [y] = jacobi(x)
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y1 = [A(1,1)-x(3) , A(1,2) , -x(1)];
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y2 = [A(2,1) , A(2,2)-x(3) , -x(2)];
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y3 = [2*x(1) , 2*x(2) , 0];
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y = [y1;y2;y3];
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end
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function [y] = fixpoint_next(x)
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y = x - inv(jacobi(x0)) * f(x);
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end
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xCur = fixpoint_next(xOld);
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x(:,N) = xCur;
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while(norm(xCur-xOld) > epsilon && N < 60)
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N = N + 1;
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xOld = xCur;
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xCur = fixpoint_next(xOld);
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x(:,N) = xCur;
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end
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end |