Store your data in array and use indices to access the data -
Es = 200*10^9; % Young's modulus of the solid of the steel(Pa)
h = 0.02; % Thickness(m)
%Define Beta as an array
Beta = (0:10)/10;
%Corresponding value of e
e = 1-((1-Beta).^2);
%As z does not depend on the loop index, bring it out of the loop
%This avoids calculating z over and over again.
z = -h/2:0.001:h/2;
figure()
for k=1:numel(Beta)
Ez = (Es*(1-(e(k).*(cos((pi*z)/h)))));
plot(z,Ez)
hold on
end
xlabel('z')
ylabel('E(z)')
title('Porousity factor: Beta')
legend('0','0.1','0.2','0.3','0.4','0.5','0.6','0.7','0.8','0.9','1','location','best')
As you learn things about MATLAB, you will find that vectorization is a powerful tool, as MATLAB is optimized for operations involving arrays. The above for loop can be vectorized as well -
e0 = e';
%What you will get below is an array, where each column will be
%Ez value calculated for corresonding value in beta
Ez0 = (Es*(1-(e0*(cos((pi*z)/h)))));
%Make a new figure to plot and observe the results
figure()
%When first input is a vector, and second input is a non-vector array
%plot() will plot each curve corresponding to each column of the second input
plot(z,Ez0)
As for the warning - You have plotted only 1 curve before using legend(), but you have included more than 1 names, so the legend() ignores the rest of the names, which is what the warning says as well.
