invalid use of operator

You are missing a ( after the second "if", and you are missing an "end" statement. That being said, my suggestion would be to use an "else" instead as that appears to be your intent. E.g.,

if ( condition )
    starrt = pitaron;
else
    ennd = pitaron;
end

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mohammad massarwe 2021-5-3

File: untitled.m Line: 1 Column: 1

Invalid use of operator.

James Tursa 2021-5-3

Get rid of the >> as Walter suggests.

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Abdul-Hamid Mohammed 2022-3-27

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https://ww2.mathworks.cn/matlabcentral/answers/820570-invalid-use-of-operator#answer_928204

在 MATLAB Online 中打开

for i=1:length(t)-1
    x(i+1)=x(i)+(a*(x^2)(i)*(1+B(x^2)(i)-q*x(i)*E(i)))*Dt;
    E(i+1)=E(i)+(z*(p*q*x(i)*E(i)-c*E(i)))*Dt;
end;
I am getting invalid use of operator with the above syntex, pls how do i resolve it. thank you.

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Abdul-Hamid Mohammed 2022-3-27

在 MATLAB Online 中打开

% Euler's Method
% Initial conditions and setup
% x(t+1)=x(t)+(a*(x(t)^2)*(1+B(x(t)^2)-q*x(t)*E(t)))*Dt
% E(t+1)=E(t)+(z*(p*q*x(t)*E(t)-c*E(t)))*Dt
%
%=======================================================================
a=1; alpha value
B=25; beta value
q=0.1; %catchability
z=0.1; %effort
p=100; %price
c=4; %cost
Dt=0.01; %delta t
timesteps=50;
t=0.1:Dt:timesteps; %array with time
for i=1:length(t)-1
    x(i+1)=x(i)+(a*(x(i)^2)*(1+B(x(i)^2)-q*x(i)*E(i)))*Dt;
    E(i+1)=E(i)+(z*(p*q*x(i)*E(i)-c*E(i)))*Dt;
end;