Hi,
First of all it's better to remove the int function from the for loop. It will make it really slow. This is what I came up with to simplify your problem. And also use drawnow if you want to plot within a for loop and thus create an animation. Try to avoid as much as possible for loops in matlab.
clear,clc
syms X I
F=int(X*sin((I*pi*X)/50),X,0,1)+int((2-X)*sin((I*pi*X)/50),X,1,2);
a=double((2/50)*subs(F,I,1:110));
%stage 3
v=1; %m/s
gif=0;
x=-20:0.1:20;
for t=0:0.1:5
for i=1:1:110
gif =gif + a(i).*sin((i*pi*(x-v*t)/50));
end
figure(1)
plot(x,gif);
grid on
xlabel('space');
ylabel('phi(x)');
title(t)
drawnow
end
A better version would be to remove the for loop for i like this
clear,clc
syms X I
F=int(X*sin((I*pi*X)/50),X,0,1)+int((2-X)*sin((I*pi*X)/50),X,1,2);
i=1:1:110;
a=double((2/50)*subs(F,I,i));
%stage 3
v=1; %m/s
x=-20:0.1:20;
for t=0:0.1:5
gif =a*sin(i'*pi*(x-v*t)/50);
figure(1)
plot(x,gif);
grid on
xlabel('space');
ylabel('phi(x)');
title(t)
drawnow
end
Making it even faster (using matrix multiplication).
Amid.
