[Getdp] Neummann boundary condition

[Lin Ji]

Hi, Christophe,
    I am still using getdp to solve 2-D accoustic wave equation in bounded
half space with Neummann boundary condition on all four sides. Recently, I
noticed that the way I specify the Neumman boundary condition in getdp should
be examined more carefully. I know that when we write out the wave equation
in weak form, the Neummann boundary function would appear in the equation as
an integral with test function on the boundary. I thought it is equivalent to
specifying Neumman boundary condition explicitly. But now, I doute it.
    I checked the reference. It seems to me there is no example for
specifying such boundary condition in the Constaint object. The Assign type
in the Constraint object seems only apply to Dirichlet boundary condition.
So, can you let me know how to specify Neummann boundary condition explicitly
in getdp in the way as specifying Dirichlet boundary condition? Thanks in
advance.

Lin

-- 
Dept. of Math., RPI
518-276,6904 (work)