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<DIV><SPAN class=265091902-24072007><FONT face=Arial
size=2>Hi,</FONT></SPAN></DIV>
<DIV><SPAN class=265091902-24072007><FONT face=Arial
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=265091902-24072007><FONT face=Arial
size=2> I would like to solve the Poisson equation (3D)
in a concentric type of cube as in the attached figure using PETSc. The solution
domain would be the shaded region only and it extends inside the cube. I would
like to have suggestions on ways to form and assemble the matrix associated with
the discretization. Also, is it a good practise to discretize the entire domain
and blank the grid points which are within the cube not in the domain
?</FONT></SPAN></DIV>
<DIV><SPAN class=265091902-24072007></SPAN> </DIV>
<DIV><SPAN class=265091902-24072007><FONT face=Arial
size=2>Regards,</FONT></SPAN></DIV>
<DIV><SPAN class=265091902-24072007><FONT face=Arial
size=2>Dominic</FONT></SPAN></DIV>
<DIV><SPAN class=265091902-24072007> </SPAN></DIV></BODY></HTML>