Why is the answer in my command window multiplying every time I press run??

1 次查看（过去 30 天）

Britney 2014-10-9

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/158058-why-is-the-answer-in-my-command-window-multiplying-every-time-i-press-run

评论： Britney 2014-10-14

So I got the correct code..I think but when I press run the answer first showed up as x2 and when I pressed run the answer showed up x4 on command window.

My function:

function x=my_newton(f,Df,x0,tol)
%f=@(x)(x.^3-cos(4*x));
%Df=@(x)((3*x^2)+(4*sin(4*x)));
x=x0;kmax=10; tol=0.5e-8;
for k=1:kmax
    d=-f(x)/Df(x);
    x=x+d;
    disp([x d])
    if abs(d)<tol, break 
    end
end
msg=sprintf('warning');
if k==kmax, disp(msg);
end

And in a separate script I run:

f=@(x)(x.^3-cos(4*x));
x=linspace(-3,7);
plot(x,f(x))
axis([-3 7 -5 10]);grid on
hold on
%--------------
f=@(x)(x.^3-cos(4*x));
Df=@(x)((3*x^2)+(4*sin(4*x)));
x=my_newton(f,Df,[-0.9],1e-8);
x=my_newton(f,Df,[-0.4],1e-8);
x=my_newton(f,Df,[0.4],1e-8);

I get correct answer in Command window but first the answer showed up in x2 and then when I pressed again run and it just multiplies....What is wrong?

6 个评论
显示 4更早的评论隐藏 4更早的评论

Andrew Reibold 2014-10-10

definitely has to be related to clearing.

Britney 2014-10-14

sorry I saw just now that you commented on my question. I figured out what was wrong. It was the disp() in my while loop. I just put a % in front of it and my code worked out fine.

Thank you for taking the time.

请先登录，再进行评论。

请先登录，再回答此问题。