don't know the problem in my while loop
2 ビュー (過去 30 日間)
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there is also another error idk about of :
Array indices must be positive integers or logical values.
Error in sym/subsref (line 890)
R_tilde = builtin('subsref',L_tilde,Idx);
iteration=0;i=1;
x=zeros(100,1);
syms f(x);
f(x) = input('donner une function : f(x)= ');
e = input('donner une la valuer de erreur : e = ');
x(1) = input('donner la valeur de depart : x1 = ');
while ( e < abs(x(i+1)-x(i)) )
iteration = iteration +1 ;
x(i+1)=x(i)-f(x(i))/diff(f(x(i)));
i=i+1;
end
disp('la value de x apartir de e est', x(i));
disp(iteration);
0 件のコメント
採用された回答
the cyclist
2022 年 1 月 1 日
You initialize the value of i to be zero.
Then you try
x(i)
which is equivalent to
x(0)
which means you are trying to access the zeroth element of x. But MATLAB indexing begins at 1, not 0, so you get that error.
8 件のコメント
the cyclist
2022 年 1 月 1 日
OK. Is the following code equivalent to your example, and give the error you see?
I removed the input functions (because they won't work here), and I also used an anonymous function instead of the symbolic function (because I don't have that toolbox).
iteration=0;
i=1;
x=zeros(100,1);
% syms f(x);
% f(x) = input('donner une function : f(x)= ');
% e = input('donner une la valuer de erreur : e = ');
% x(1) = input('donner la valeur de depart : x1 = ');
f = @(x) x.^3 - 10;
e = 0.001;
x(1) = 3;
while ( e < abs(x(i+1)-x(i)) )
iteration = iteration +1 ;
x(i+1)=x(i)-f(x(i))/diff(f(x(i)));
i=i+1;
end
disp('la value de x apartir de e est', x(i));
disp(iteration);
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