Undefined function 'BisectionRoot' for input arguments of type 'function_handle'.

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Jaycie Bishop 2020-9-15

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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/594151-undefined-function-bisectionroot-for-input-arguments-of-type-function_handle

评论： Jaycie Bishop 2020-9-15

Code from part 1 of problem (works fine):

%% From 3.2 %%
% Bisection Method
high = 0; %given initial value
low = 1; %given initial value
f = @(x) x - 2*exp(-x); %function
mid = (high + low)/2; % guess
it = 1; %iteration
tol = 0.001; %tolerance
it_max = 5; %max iterations
x1 = mid;
x2 = 0;
x3 = 0;
x4 = 0;
while (mid > tol && it < it_max)
    f_mid = f(mid);
    if f_mid < 0
        high = mid;
    else
        low = mid;
    end
    mid = (high + low) / 2; 
    if it == 1
        x2 = mid;
    elseif it == 2
            x3 = mid;
    elseif it == 3
        x4 = mid;
    elseif it == 4
        x5 = mid;
    end
it = it + 1;
end
x_bisection = [x1 x2 x3 x4];
%%Code from Current Problem%%
%% Probelm 3.16 %%
function Xs = BisectionRoot(Fun, a, b, tol) %% <---WHERE THE ERROR IS
fa = Fun(a);
fb = Fun(b);
if fa*fb > 0
    Xs = ('Error')
else
    n = ceil((log10(b-a)-log10(tol))/log10(2)); %calculating # of iterations
    for i = 1:n
        Xs = (a+b)/2;
        f_Xs = Fun(Xs);
        if f_Xs == 0
            break
        end
        if fa*f_xs < 0
            b = Xs;
        else
            a = Xs;
            fa = f_Xs;
        end
    end
end
end

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Jaycie Bishop 2020-9-15

This is being done on "MatlabGrader" and there is no where (that I see) that I can be inputting a file in the path like I would if I was regularly coding on matlab. So I think I need to adjust the code in order to not call a file.

Jaycie Bishop 2020-9-15