Trouble utilising direct search method to my function

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Sohail Nadeem 2021-12-30

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Hello,

I am attempting to utilise code from my professor to solve a direct search optimisation problem.

The function i am utilising is f(x) = 2x^2 +3exp(-x) in the interval of 0<x<1

I am attempting to utilise the equal interval approach but my problem is utilising the code provided.

What i attempoted was typing in my function in the [] after the function and my interval in the () after EI.

I understand the theory but im struggling on the implementation. Thank you.

function [] = EI()
p         = 2;                                      % Edit integer to select 
problem
[a,b,f,e] = problem(p); clc
X = linspace(a,b,4); F = f(X); R = [0,X,F,(X(1)+X(4))/2; zeros(30,10)]; 
for i = 1:30
    if F(2) < F(3)
        X = linspace(X(1),X(3),4); F = f(X);
    else
        X = linspace(X(2),X(4),4); F = f(X);
    end
    R(i+1,:) = [i,X,F,(X(1)+X(4))/2]; if abs(X(4)-X(1)) <= e, break, end
end
R  = R(1:i+1,:);                                    % Build tabulated display
i  = R(:,1);
x1 = R(:,2);
x2 = R(:,3); f2 = R(:,7);
x3 = R(:,4); f3 = R(:,8); Midpoint = R(:,10);
x4 = R(:,5);
table(i,x1,x2,x3,x4,f2,f3,Midpoint)
    function [a,b,f,e] = problem(i)                     % Add additional case items
        to define more problems
        
        switch i
            case 1
                a = 1;
                b = 2;
                f = @(x) -exp(-x).*sinh(x/2);
                e = 0.001;
            case 2
                a = 0;
                b = 1;
                f = @(x) 2*x.^2+3*exp(-x);
                e = 0.001;
            case 3
                a = 1;
                b = 10;
                f = @(x) 660./x+2*pi*x.^2;
                e = 0.001;
            case 4
                a = 1;
                b = 10;
                f = @(x) 330./(pi*x.^2)+4*pi*x;
                e = 0.001;
            case 5
                a = 0;
                b = 1.2;
                f = @(x) -2*x.*sqrt(2.4^2-(1.2+x).^2);
                e = 0.001;
        end
    end
end