Hello, The number of unknowns after discretization is 60x85x220 = 1.12 million nodes. This should be the size of an eigenfunction vector in 3d.
Em seg, 1 de jul de 2019 às 20:26, Mark Adams <[email protected]> escreveu: > 3D uses a lot more memory. This is a crazy number (18446744069467867136). > How large is your system? > > On Mon, Jul 1, 2019 at 7:20 PM Rodrigo Piccinini via petsc-users < > [email protected]> wrote: > >> Hello, >> >> I'm trying to solve for the first ten smallest eigenvalues of a diffusion >> equation in a 3d heterogeneous medium (varying diffusion coefficient), but >> I'm getting an error message: >> >> Traceback (most recent call last): >>> File "eigendrake_spe10_v2.py", line 121, in <module> >>> es.solve() >>> File "SLEPc/EPS.pyx", line 1132, in slepc4py.SLEPc.EPS.solve >>> petsc4py.PETSc.Error: error code 55 >>> [0] EPSSolve() line 136 in >>> /tmp/pip-req-build-6t_4bkg3/src/eps/interface/epssolve.c >>> [0] EPSSetUp() line 269 in >>> /tmp/pip-req-build-6t_4bkg3/src/eps/interface/epssetup.c >>> [0] STSetUp() line 271 in >>> /tmp/pip-req-build-6t_4bkg3/src/sys/classes/st/interface/stsolve.c >>> [0] STSetUp_Shift() line 119 in >>> /tmp/pip-req-build-6t_4bkg3/src/sys/classes/st/impls/shift/shift.c >>> [0] KSPSetUp() line 391 in >>> /tmp/pip-req-build-070lpqqd/src/ksp/ksp/interface/itfunc.c >>> [0] PCSetUp() line 932 in >>> /tmp/pip-req-build-070lpqqd/src/ksp/pc/interface/precon.c >>> [0] PCSetUp_LU() line 99 in >>> /tmp/pip-req-build-070lpqqd/src/ksp/pc/impls/factor/lu/lu.c >>> [0] MatLUFactorSymbolic() line 3111 in >>> /tmp/pip-req-build-070lpqqd/src/mat/interface/matrix.c >>> [0] MatLUFactorSymbolic_SeqAIJ() line 366 in >>> /tmp/pip-req-build-070lpqqd/src/mat/impls/aij/seq/aijfact.c >>> [0] PetscMallocA() line 390 in >>> /tmp/pip-req-build-070lpqqd/src/sys/memory/mal.c >>> [0] MatLUFactorSymbolic_SeqAIJ() line 366 in >>> /tmp/pip-req-build-070lpqqd/src/mat/impls/aij/seq/aijfact.c >>> [0] Out of memory. Allocated: 0, Used by process: 14097043456 >>> [0] Memory requested 18446744069467867136 >> >> >> I'm using code from Firedrake Project <https://www.firedrakeproject.org/> >> (finite-element method) to discretize the equations. >> My code is available here: >> https://github.com/rbpiccinini/codes/blob/master/eigendrake/eigendrake_spe10_v2.py >> >> The code was run with 64GB available as RAM memory. The requested memory >> seems to be abnormally high, though. >> I'm able to solve for the eigenvalues of a 2d smaller problem. However, >> if I try to solve the 3d problem, I get the out of memory error. >> >> Could anybody help me understand the issue? >> >> Thanks in advance. >> >> -- >> Rodrigo >> > -- -- Rodrigo
