I need help with my code. I don't understand what the error code is for. This is the error code Error: File: Lab1Modeling.m Line: 18 Column: 12 The expression to the left of the equals sign is not a valid target for an assignment.

t = 0;
Cai = 4;
Cbi = 1;
P = .15;
A = .85;
N1 = Cai;
N2 = Cbi;
J3 = 0;
 count = 1;
 while(count < 11)
     {
        J3 = N1/t;
        Ca0 = -(J3/P)+Cai;
        count = count+1;
        time = time +1;
        plot(Ca0, time);
        xlabel('Time (sec)');
        ylabel('Ca0 (moles)');
        if(time = 11)
        {
           break;
        } 
       
        

Answer 1

[Jacob Ward]

There are a few problems with your code as written:

First, you are using curly braces instead of using the while/end or if/end syntax that you are supposed to use in MATLAB. You also don't need parentheses for your if and while statement and I think you want a double equals sign for your equals comparison. It should look like this:

if time == 11
    break
end

Your while loop should be:

while count < 11
    %insert the rest of your code here
end

Finally, you initialize t=0 but I think you meant time=0 because you use the variable 'time' later.

All in all, your code should look like the following:

time = 0;
Cai = 4;
Cbi = 1;
P = .15;
A = .85;
N1 = Cai;
N2 = Cbi;
J3 = 0;
count = 1;
 while count < 11
        J3 = N1/t;
        Ca0 = -(J3/P)+Cai;
        count = count+1;
        time = time +1;
        plot(Ca0, time);
        xlabel('Time (sec)');
        ylabel('Ca0 (moles)');
        if time == 11
           break
        end
 end

Answer 2

[madhan ravi]

% No loops needed:
Cai = 4;
Cbi = 1;
P = .15;
A = .85;
N1 = Cai;
N2 = Cbi;
Start = 0;
End = 11; 
Increment = 1; % if you make it small you would get a finer graph
t=Start:Increment:End;
J3 = N1./t;
Ca0 = -(J3/P)+Cai;
plot(Ca0, t,'-ob');
xlabel('Time (sec)');
ylabel('Ca0 (moles)');