The code returns a value in the form of "theta_3b(x, z) =.". How can I get this to return just theta_3b=

syms f g x y z
% % % % % Temperature Formula 3b % % % % %
theta_3b=0;
for n=0:25
    t=0;
    beta6 = (n*pi)/H;
    eta6 = (((2*pi)/L)*(n+0.5));
    mew6 = -1036;
    lamda6 =  (beta6.^2)+(eta6.^2)+(mew6.^2);
    
    f(x,y,z) = sin(beta6*z).*cos(eta6*x).*sin(mew6*y).*cos(mew6*y);
    C_nmp_numerator6 = int(int(int(f,z,[0 H]),y,[0 W]),x,[0 (L/2)]);
    g(x,y,z) = ((cos(mew6*y)^2).*sin(mew6*y) - ((h/(k*mew6)).*(sin(mew6*y)^2).*cos(mew6*y)));
    C_nmp_denominator6 = ((L*H)/8)* (int(g,y,[0 W]));
    C_nmp6 = C_nmp_numerator6/C_nmp_denominator6;
    
    theta_3b = theta_3b+(C_nmp6*(sin(beta6*z)*cos(eta6*x)*((cos(mew6*y)-(h/(k*mew6))*sin(mew6*y)))*exp(-(lamda6^2)*alpha*t)));
    
end
theta_3b = vpa(subs(theta_3b, {x,y,z}, {X,Y,Z}))

Answer 1

[Abhaya]

Hi Clayton,

The variable ‘theta_3b’ derives its type from variable ‘C_nomp6’, which is of type ‘symfun’. This is why, when you display variable ‘theta_3b’, the associated symbols are shown alongside its name.

To display only the expression associated with the variable ‘theta_3b’ you can use MATLAB ‘findSymType’ function.

findSymType(theta_3b,'expression') 

For more information, please follow the MATLAB documentation for ‘findSymType’.

https://www.mathworks.com/help/symbolic/sym.findsymtype.html

Hope it resolves your query.

Answer 2

[Walter Roberson]

theta_3b = vpa(subs(theta_3b, {x,y,z}, {X,Y,Z}));

fprintf('theta_3b = %s\n', char(theta_3b))