plot command is not work in Gauss Seidel Method

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A = [
1 0 -1 0 0 0 0
-1 1 1 0 0 0 0
0 -1 2 -1 0 0 0
0 -1 0 2 0 1 0
0 -1 -1 0 2 1 1
0 0 1 -1 0 2 -1
0 0 0 -1 1 -1 2
];
b = [0 0 0 0 0 20 0]';
x=[1 1 1 1 1 1 1];
n=size(x,1);
normVal=Inf;
tol=1e-5; itr=0;
%%Gauss Seidel Method
while normVal>tol
x_old=x;
for i=1:n
sigma=0;
for j=1:i-1
sigma=sigma+A(i,j)*x(j);
end
for j=i+1:n
sigma=sigma+A(i,j)*x_old(j);
end
x(i)=(1/A(i,i))*(b(i)-sigma);
end
itr=itr+1;
normVal=norm(x_old-x);
end
%%
fprintf('system solution : \n%f\n%f\n%f\n%f in %d iterations',x,itr);
hold on
plot(itr,x, '+')
xlim([0 10])
ylim([0 2])
hold off
end

Accepted Answer

John D'Errico
John D'Errico on 4 Dec 2020
When you tell us that something does not work, you need ot explain why you THINK it does not work. In fact, plot worked perfectly well there. At least, it tiried to work as well as it could.
itr
itr =
2
x
x =
0 1 1 1 1 1 1
plot(itr,x, '+')
So itr is the number 2. x is a vector. What did you expect it to do?
  2 Comments
suketu vaidya
suketu vaidya on 4 Dec 2020
easy way i try to plot ans of gauss seidel method

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More Answers (1)

suketu vaidya
suketu vaidya on 4 Dec 2020
right ans is
hold on
plot(x,'o')

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