Thank you for your prompt reply.
I'm solving the 2D Helmholtz problem on a Cartesian plane. u''(x,y)+q*u(x,y)=f(x,y)
Above governing equation, f(x,y) is external or internal source and Dirac Delta Function.
I want to compare analytical solution with numerical solution.
I have analytical solution.
To obtain numerical solution, Dirac Delta Funtion code is needed.
I know the function can not be expressed directly.
So, in detail, my question is how is the approximated expression of Dirac Delta Function.
Thank you in advance