Index exceeds the number of array elements (1).

Hello I am getting the following error when running this function in MATLAB:

Index exceeds the number of array elements (1).

Error in hw6_1 (line 11)

err = min(abs(f(a)),abs(f(b)));

Thank you!!

function [root, A, B] = hw6_1(f, a, b, numsegs)

%f = function
%a = lower limit of the initial range
%b = upper limit of the intial range
%numsegs = number of subranges 
%root=number of roots
%A=vector of lower limits
%B=vector of upper limits

A=a;
B=b;
tol = 0.001;
err = min(abs(f(a)),abs(f(b)));
while (err >= tol)
    dx = (b-a)/numsegs;
    for i = 1:numsegs
        x = a + (i-1)*dx;
        prod = f(x) * f(x+dx);
        if (prod <= 0)
            a = x; %identify new subrange
            b = x+dx;
            A=[A,a];
            B=[B,b];
        end
    end
    err = min(abs(f(a)),abs(f(b)));
end
if (abs(f(a)) < abs(f(b)))
    root = a;
else
    root = b;
end

[KSSV]

What input you gave?

[Walter Roberson]

You passed in a scalar numeric value for the first parameter, instead of passing in a function handle.

[Niccole Theriault]

Hi! I'm sorry, I'm pretty new to this. How do I fix it?

I need to have the function set to the user can input a funtion (f=2*x^2 for example), the bounds (a&b) and the number of segments to divide the bounds into.

Thanks again!

[Walter Roberson]

Do not pass

2*x^2

as the first parameter. Pass

@(x)2*x.^2