You did not include an index for P, so you just overwrite the same P every iteration. You should have done:
P(i) = (A.*B)/(C*D);
However, you can vectorize the code like this:
phi = [pi/6 , pi/3, pi/2, 2*pi/3, 5*pi/6, pi, 7*pi/6, 4*pi/3, 3*pi/2, 5*pi/3, 11*pi/6]
P = myfile(phi) % Call the myfile function
function P = myfile(phi)
A = 6*(0.8).*sin(phi);
B = 2+(0.8).*cos(phi);
C = 2+(0.8).^2 * ones(1, length(phi));
D = (1+0.8.*cos(phi)).^2;
P = (A.*B)./(C.*D);
figure
plot(phi,A, '*-', 'LineWidth', 2);
hold on;
plot(phi,B, '*-', 'LineWidth', 2);
plot(phi,C, '*-', 'LineWidth', 2);
plot(phi,D, '*-', 'LineWidth', 2);
plot(phi,P, '*-', 'LineWidth', 4);
xlabel('Domain');
ylabel('Pressure');
title('non-dimensional pressure');
legend('A', 'B', 'C', 'D', 'P');
grid on;
end
I'm showing the individual A, B, C, and D, just for interest. You just have to change the definition of C slightly. Vectorization is something you should learn as it's one of the most powerful features of modern languages.
