MATLAB: Very strange error of for loop

MATLAB

I made this kind structure code

but the result is not I had expecetd

k=1;
for i=1:1:100
  
    if(i==1)
        a=zeros(size(i));
        b=zeros(size(i));
    end
    
    a(k)=sin(i);
    b(k)=a(k)
    k=k+1
end

a(k) display the sin wave

but b(k) dispay only one constant value

like y=3

what happend to my code?

Best Answer

You did not include the plot call you are using.

If you are plotting:

figure
plot(a,b)

it will show a straight line from (-1,-1) to (1,1) because both ‘a’ and ‘b’ have the same values.

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MATLAB: Secant Method executing error.

Your file, Secant.m, is a script: any .m file whose first non-comment is not "function" or "classdef" is considered a script. You cannot pass parameters when you call scripts. However, your very first line of code attempts to call your file Secant.m as if it is a function.

Note that if you somehow succeeded in calling Secant from Secant.m then the first thing the invoked Secant would do would be to call Secant, and the first that that would do would be to call Secant, and so on, until MATLAB eventually notices that you are calling the same routine over and over again and terminates the function. You need to be very careful when you have a file invoke itself!

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In your case its simply a=i but you have asked it for clarifcation so the illustration is as follows:

i=17.890:0.005:17.920;
a=zeros(size(i)); % preallocate
for k=1:numel(i)
    a(k)=i(k);  % index with loop iterator (k)
end
a

Best Answer

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