Integration error while running a script in Matlab 2015

I am using matlab 2015 and while running the following script file I am getting error: error in sym/subsref(line 771) R_title = ......

please help!

%%%%Script%%%%%
clear all; close all; clc 
syms x g L R EIo rho Ao xc mR

psi=(x/L)^2
dpsi=diff(psi,x);
ddpsi=diff(dpsi,x);
xc=0.8*L
me=int((rho*Ao(1-(0.5*x)/L))*(psi)^2,x,0,L)+mR*subs(psi,x,xc);
ke=int(EIo*(1-(0.2*((x/L)^2)))*ddpsi^2,x,0,L)
kg=int(mR*g*(dpsi)^2,x,0,L)
Qv=int((pt*(x/L))*psi,x,0,L)

Answer 1

[Ameer Hamza]

me=int((rho*Ao*(1-(0.5*x)/L))*(psi)^2,x,0,L)+mR*subs(psi,x,xc);
            % ^ insert * here. It is missing in your code

[Sadia]

Even doing that its still giving error, same code is running well in matlab 2018.

[Walter Roberson]

Your code starts with clear all so we know that there cannot possibly be any variables in the workspace that are left over from the previous run.

Your code uses

Qv=int((pt*(x/L))*psi,x,0,L)

pt is not a variable in the code and is not any Mathworks function.

If your code ran properly in R2018a then we must conclude that somewhere on your MATLAB path, you have a pt.m function that is happy to run with no input variables, and returns either a numeric value or a symbolic value. You will need to provide the code for your pt.m for us to test with.

[Sadia]

Thank you Mr. Walter Roberson for such clear explanation. I think the person I asked to run this code in his computer has made pt as veriable but my matlab is still giving error. So i am thinking to install latest version.

[Ameer Hamza]

Have you defined pt as variable on your computer?