H := a -> piecewise(a>=0,1):
f1 := y->(H(y-1*Pi)-H(y-2*Pi))*sin(y)^2:
g2:= int(g1, y= 0..100):
E2:= unapply(Int(g5, x= 0..100, epsilon= 1e-4, digits= 7), t):
CodeTools:-Usage( plot(E2, 0..20, numpoints= 50, labels= [t, E]));
The above mentioned code should give constant figure, but it takes a lot of time and not accurate.
If you can help me to improve these codes, I would be pleased.