Hello everyone,

My question might be trivial for you but I really could not find any solution online. In an academic assignment, the load function acting on top of a beam contains dirac function and its derivatives. What I want is that the dirac function, Dirac(x-a1), is equal to 1 when x=a1, but all I get is Dirac(0.). 

I solved the same problem with Heaviside function with the NumericEventHandler but did not find anything about Dirac delta function.

My goal is to also plot this load function ("q" in my case) along a beam of 5 meters length. When I tried it looks like the dirac delta function are not considered at all.

restart:
with(plots):
NumericEventHandler(invalid_operation=`Heaviside/EventHandler`(value_at_zero=1/2)):
alias(delta=Dirac):
q:=3-0.2*x+varV1*delta(x-a1)+varV3*delta(x-a3)+EI2*varPhi2*delta(2,(x-a2))+EI2*varW2*delta(3,(x-a3));
            q := 3 - 0.2 x + varV1 delta(-x + a1) + varV3 delta(-x + a3)

   + EI2 varPhi2 delta(2, -x + a2) - EI2 varW2 delta(3, -x + a3)

a1:=1:a2:=3:a3:=2:
x:=a2:q;
                 2.4 + EI2 varPhi2 delta(2, 0)

x:='x':plot(q,x=0..5);
 

Thank you in advance.