need some help matlab code has an error

Question

edward desmond muyomba 2020-4-29

0
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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/521605-need-some-help-matlab-code-has-an-error

评论： edward desmond muyomba 2020-4-29

A = [6 2 1 1;2 7 1 2;3 2 8 1;1 2 6 9];
B = [6;4;5;3];
maxitr = 100;
tolx = 1.0e-5;
n = length(A);
x = zeros(n,1);
err = zeros(n,1);
for itr = 1:maxitr
        for i = 1:n
            xold = x(i);
            x (i) = (b(i) - (A(i,1:i-1) *x(1:i-1) +A(i,i+1:n)*x(i+1:n))) /A(i,i);
            err(i) = abs(x(i)   - xold);
        end
        if (max(err)<tolx)
            fprint('\n Error @  last iteration = %f',max(err));
            fprint('\n\n solution found @ iteration no. =%d ',itr);
            fprint('n\n solution Vector : \n');
            disp(x);
            break
        end
end

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Answer 1

Tommy 2020-4-29

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https://ww2.mathworks.cn/matlabcentral/answers/521605-need-some-help-matlab-code-has-an-error#answer_429085

在 MATLAB Online 中打开

(1) Use B where you have b.

(2) Change fprint to fprintf.

A = [6 2 1 1;2 7 1 2;3 2 8 1;1 2 6 9];
B = [6;4;5;3];
maxitr = 100;
tolx = 1.0e-5;
n = length(A);
x = zeros(n,1);
err = zeros(n,1);
for itr = 1:maxitr
        for i = 1:n
            xold = x(i);
            x (i) = (B(i) - (A(i,1:i-1) *x(1:i-1) +A(i,i+1:n)*x(i+1:n))) /A(i,i);
            err(i) = abs(x(i)   - xold);
        end
        if (max(err)<tolx)
            fprintf('\n Error @  last iteration = %f',max(err));
            fprintf('\n\n solution found @ iteration no. =%d ',itr);
            fprintf('n\n solution Vector : \n');
            disp(x);
            break
        end
end