While running the code, I am getting error expression as, 'The expression to the left of the equals sign is not a valid target for an assignment'.

clc
clear all
syms q  TOT
D=1000;
P=3200;
S=400;
A0=25;
Cv=20;
Cb=25;
Rc=3;
Cs=30;
MUv=0.2;
MUb=0.2;
sigma=7;
k=2.33;
L0=8;
Gamma=0.05;
Delta=5;
is=0.02;
iv=0.02;
ic=0.06;
M=0.1;
Z(L)=0;
n=1;
L=8;
Alpha=20;
Beta=0.6250;
q=0;
for i=1:10
    q=sqrt(((2*D)*((Alpha+Beta*ln(L))+(s/n)+Z(L)+((D*M^2)/2)*(Cb*ic-Cs*is)))/((MUb*Cb)+(MUv*Cv)*(n*(1-(D/P))-1+((2*D)/P))))
    TOT=(D/q)*((Alpha+Beta*ln(L))+(s/n)+Z(L)+((D*M^2)/2)*(Cb*ic-Cs*is))+(q/2)*((MUb*Cb)+(MUv*Cv)*(n*(1-(D/P)-1+((2*D)/P)+(Cb*ic))+(MUb*Cb*k*sigma*sqrt(L))=(Rc*Gamma*D)+(Cb*D*M*(im-ic))
end

The answer is q=332, TOT=3240.

[Ameer Hamza]

What is the intention to put this 2nd '=' operator?

[shunmugam hemalatha]

I have corrected the mistake that you have pointed. But i don't know how to enter the data Z(L). Still the error shows that (Undefined function or variable 'L')

Z(L)=0;

[madhan ravi]

Why is there a loop ??

Answer 1

[Aayush Shah]

Hi Shunmugam,

My understanding of your question is that you are getting an error while assigning a value after doing the computations. The reason for it is that you’re using two assignment (=) operators in a single line. The ‘=’ sign at col 156(i.e., before ‘Rc’) is wrong. Another error you might encounter after changing the above code is from this line:

Z(L)=0; 
n=1;  
L=8;

You will get an error because you’re trying to use the value of ‘L’ before assigning it any value. Interchange the lines and your issue would be solved.

[shunmugam hemalatha]

Thank you verymuch Sir for your answer.

Its so helpful to me to recover the mistakes.

Thank you.