Why am I getting an error here?

clear all 
close all
clc

% constants and data
g = 9.81; D = 75; rho= 1000;
Z = 0:12.5:75;
w = [122 130 135 160 175 190 200];

%% Function handle for pressure, p(z)
p = @(z) rho*g*(D-z);

%% computing ft and d
I1 = @(z) rho*g*w(Z==z)*(D-z); % function inside ft integral
I2 = @(z) rho*g*z*w(Z==z)*(D-z); % function in the numerator of d
% evaluating the integrals
ft = simpson(I1,0,D) % integrate and get ft
d = simpson(I2,0,D)/simpson(I1,0,D) % integrate and divide to get d

%% function to compute the simpson's rule integral for function f on interval [a,b]
%
function I = simpson(f,a,b)
h = Z(2)-Z(1); % compute step size h
n = (b-a)/h; % compute number of intervals n


F = 0; % initialize the sum
for i = 0:n
if i==0 || i==n
c =1; % coefficient for first and last terms
elseif mod(i,2)~=0
c = 4; % coefficient for odd terms
elseif mod(i,2)==0
c = 2; % coefficient for even terms
end

F = F + c*f(a+i*h);
end

I = (h/3)*F; % final integral (sum)

end
end

Function definitions in a script must appear at the end of the file.
Move all statements after the "simpson" function definition to before the first local function definition.

Error in connector.internal.fevalMatlab

Error in connector.internal.fevalJSON

Answer 1

[Walter Roberson]

function I = simpson(f,a,b)

depth 1

for i = 0:n

depth 2

if i==0 || i==n

depth 3

elseif mod(i,2)~=0

depth 3

elseif mod(i,2)==0

depth 3

end

depth 2

end

depth 1

end

depth 0 -- function has ended

end

depth negative 1. This end statement as no matching control structure