[petsc-users] SNES Line search: fixing the non zero solution values of dirichlet nodes during line search
Ashish Patel
ashish.patel at onscale.com
Fri Jun 19 17:15:03 CDT 2020
Dear PETSc users,
We use PETSc as part of a finite element method program and we are trying
to properly implement Dirichlet boundary conditions for non-linear,
transient problems. We find that when we use a line search method it also
changes the non-zero solution value of Dirichlet nodes as it steps through
the line search iteration. I was wondering if there is a way to freeze
some index sets of a vector from changing during the line search operation?
We are using the TS framework to setup the problem and use
'MatZeroRowsColumns' to set the diagonal of the jacobian to 1 for the
dirichlet nodes and set the RHS as increment of
(Dirichlet_value-solution_value). This works when the line search method is
turned off by using '-snes_linesearch_type basic' however using the default
'bt' linesearch, the TS diverges with error shown below. In a separate
implementation if we overwrote the dirichlet nodes of the solution vector
in TS residual function with the Dirichlet values then the 'bt' line
search method converged to the right solution. However we would like to
avoid modifying the internal PETSc vector in our implementation.
0 TS dt 1. time 0.
0 SNES Function norm 2.378549386020e+03
Line search: gnorm after quadratic fit 4.369235425165e+03
Line search: Cubic step no good, shrinking lambda, current gnorm
2.385369069060e+03 lambda=1.0000000000000002e-02
Line search: Cubically determined step, current gnorm
2.373925008934e+03 lambda=3.8846250444606093e-03
1 SNES Function norm 2.373925008934e+03
Line search: gnorm after quadratic fit 5.006914179995e+03
Line search: Cubic step no good, shrinking lambda, current gnorm
2.420957096780e+03 lambda=1.0000000000000002e-02
Line search: Cubic step no good, shrinking lambda, current gnorm
2.376034946750e+03 lambda=1.6129422079664700e-03
Line search: Cubic step no good, shrinking lambda, current gnorm
2.374313344729e+03 lambda=4.8465026740690043e-04
Line search: Cubic step no good, shrinking lambda, current gnorm
2.373999473242e+03 lambda=1.5857251532828948e-04
Line search: Cubically determined step, current gnorm
2.373921668024e+03 lambda=5.8116507162753387e-05
2 SNES Function norm 2.373921668024e+03
Line search: gnorm after quadratic fit 4.771035112853e+03
Line search: Cubic step no good, shrinking lambda, current gnorm
2.410650718394e+03 lambda=1.0000000000000002e-02
Line search: Cubic step no good, shrinking lambda, current gnorm
2.375104094198e+03 lambda=1.8983783738011522e-03
Line search: Cubic step no good, shrinking lambda, current gnorm
2.374049151562e+03 lambda=7.0688528086485479e-04
Line search: Cubic step no good, shrinking lambda, current gnorm
2.373935090907e+03 lambda=2.9132722794896019e-04
Line search: Cubically determined step, current gnorm
2.373921032081e+03 lambda=1.2527602265373028e-04
3 SNES Function norm 2.373921032081e+03
Line search: gnorm after quadratic fit 5.117914832660e+03
Line search: Cubic step no good, shrinking lambda, current gnorm
2.422635362094e+03 lambda=1.0000000000000002e-02
Line search: Cubic step no good, shrinking lambda, current gnorm
2.375923870970e+03 lambda=1.5769887508300913e-03
Line search: Cubic step no good, shrinking lambda, current gnorm
2.374287081592e+03 lambda=4.8018017100729705e-04
Line search: Cubic step no good, shrinking lambda, current gnorm
2.373999131160e+03 lambda=1.5908966655977892e-04
Line search: Cubic step no good, shrinking lambda, current gnorm
2.373930608274e+03 lambda=5.7603977147935371e-05
Line search: Cubic step no good, shrinking lambda, current gnorm
2.373922022038e+03 lambda=2.3884787050507805e-05
Line search: Cubic step no good, shrinking lambda, current gnorm
2.373921396636e+03 lambda=1.0282405393471519e-05
Line search: Cubic step no good, shrinking lambda, current gnorm
2.373921173719e+03 lambda=4.3868704034012554e-06
Line search: Cubic step no good, shrinking lambda, current gnorm
2.373921091304e+03 lambda=1.8774991151727107e-06
Line search: Cubic step no good, shrinking lambda, current gnorm
2.373921057168e+03 lambda=8.0331628193813397e-07
Line search: Cubic step no good, shrinking lambda, current gnorm
2.373921042769e+03 lambda=3.4377811174560817e-07
Line search: Cubic step no good, shrinking lambda, current gnorm
2.373921036645e+03 lambda=1.4712421886880395e-07
Line search: Cubic step no good, shrinking lambda, current gnorm
2.373921034032e+03 lambda=6.2965363212312132e-08
Line search: Cubic step no good, shrinking lambda, current gnorm
2.373921032916e+03 lambda=2.6947718250469261e-08
Line search: Cubic step no good, shrinking lambda, current gnorm
2.373921032438e+03 lambda=1.1533043989179318e-08
Line search: Cubic step no good, shrinking lambda, current gnorm
2.373921032233e+03 lambda=4.9359018284334258e-09
Line search: Cubic step no good, shrinking lambda, current gnorm
2.373921032146e+03 lambda=2.1124641857409436e-09
Line search: Cubic step no good, shrinking lambda, current gnorm
2.373921032109e+03 lambda=9.0409137304143975e-10
Line search: Cubic step no good, shrinking lambda, current gnorm
2.373921032093e+03 lambda=3.8693264359674819e-10
Line search: Cubic step no good, shrinking lambda, current gnorm
2.373921032086e+03 lambda=1.6559911204766632e-10
Line search: Cubic step no good, shrinking lambda, current gnorm
2.373921032083e+03 lambda=7.0873187020534353e-11
Line search: Cubic step no good, shrinking lambda, current gnorm
2.373921032081e+03 lambda=3.0332192901757729e-11
Line search: Cubic step no good, shrinking lambda, current gnorm
2.373921032081e+03 lambda=1.2981600435512875e-11
Line search: Cubic step no good, shrinking lambda, current gnorm
2.373921032081e+03 lambda=5.5559212521628090e-12
Line search: Cubic step no good, shrinking lambda, current gnorm
2.373921032081e+03 lambda=2.3777380405336958e-12
Line search: Cubic step no good, shrinking lambda, current gnorm
2.373921032081e+03 lambda=1.0176091649134191e-12
Line search: Cubic step no good, shrinking lambda, current gnorm
2.373921032081e+03 lambda=4.3555419789721080e-13
Line search: unable to find good step length! After 27 tries
Line search: fnorm=2.3739210320805191e+03,
gnorm=2.3739210320805323e+03, ynorm=8.5698020038772756e+03,
minlambda=9.9999999999999998e-13, lambda=4.3555419789721080e-13, initial
slope=-5.6355010665542409e+06
SNES Object: 1 MPI processes
type: newtonls
maximum iterations=50, maximum function evaluations=10000
tolerances: relative=1e-08, absolute=1e-50, solution=1e-08
total number of linear solver iterations=4
total number of function evaluations=48
norm schedule ALWAYS
SNESLineSearch Object: 1 MPI processes
type: bt
interpolation: cubic
alpha=1.000000e-04
maxstep=1.000000e+08, minlambda=1.000000e-12
tolerances: relative=1.000000e-08, absolute=1.000000e-15,
lambda=1.000000e-08
maximum iterations=40
KSP Object: 1 MPI processes
type: preonly
maximum iterations=10000, initial guess is zero
tolerances: relative=1e-05, absolute=1e-50, divergence=10000.
left preconditioning
using NONE norm type for convergence test
PC Object: 1 MPI processes
type: cholesky
out-of-place factorization
tolerance for zero pivot 2.22045e-14
matrix ordering: natural
factor fill ratio given 0., needed 0.
Factored matrix follows:
Mat Object: 1 MPI processes
type: mumps
rows=38154, cols=38154
package used to perform factorization: mumps
total: nonzeros=7080060, allocated nonzeros=7080060
total number of mallocs used during MatSetValues calls=0
MUMPS run parameters:
SYM (matrix type): 2
PAR (host participation): 1
ICNTL(1) (output for error): 6
ICNTL(2) (output of diagnostic msg): 0
ICNTL(3) (output for global info): 0
ICNTL(4) (level of printing): 0
ICNTL(5) (input mat struct): 0
ICNTL(6) (matrix prescaling): 7
ICNTL(7) (sequential matrix ordering):7
ICNTL(8) (scaling strategy): 77
ICNTL(10) (max num of refinements): 0
ICNTL(11) (error analysis): 0
ICNTL(12) (efficiency control): 0
ICNTL(13) (efficiency control): 0
ICNTL(14) (percentage of estimated workspace increase): 20
ICNTL(18) (input mat struct): 0
ICNTL(19) (Schur complement info): 0
ICNTL(20) (rhs sparse pattern): 0
ICNTL(21) (solution struct): 0
ICNTL(22) (in-core/out-of-core facility): 0
ICNTL(23) (max size of memory can be allocated locally):0
ICNTL(24) (detection of null pivot rows): 0
ICNTL(25) (computation of a null space basis): 0
ICNTL(26) (Schur options for rhs or solution): 0
ICNTL(27) (experimental parameter): -32
ICNTL(28) (use parallel or sequential ordering): 1
ICNTL(29) (parallel ordering): 0
ICNTL(30) (user-specified set of entries in inv(A)): 0
ICNTL(31) (factors is discarded in the solve phase): 0
ICNTL(33) (compute determinant): 0
ICNTL(35) (activate BLR based factorization): 0
ICNTL(36) (choice of BLR factorization variant): 0
ICNTL(38) (estimated compression rate of LU factors): 333
CNTL(1) (relative pivoting threshold): 0.01
CNTL(2) (stopping criterion of refinement): 1.49012e-08
CNTL(3) (absolute pivoting threshold): 0.
CNTL(4) (value of static pivoting): -1.
CNTL(5) (fixation for null pivots): 0.
CNTL(7) (dropping parameter for BLR): 0.
RINFO(1) (local estimated flops for the elimination after
analysis):
[0] 2.73979e+09
RINFO(2) (local estimated flops for the assembly after
factorization):
[0] 1.08826e+07
RINFO(3) (local estimated flops for the elimination after
factorization):
[0] 2.73979e+09
INFO(15) (estimated size of (in MB) MUMPS internal data for
running numerical factorization):
[0] 94
INFO(16) (size of (in MB) MUMPS internal data used during
numerical factorization):
[0] 94
INFO(23) (num of pivots eliminated on this processor after
factorization):
[0] 38154
RINFOG(1) (global estimated flops for the elimination after
analysis): 2.73979e+09
RINFOG(2) (global estimated flops for the assembly after
factorization): 1.08826e+07
RINFOG(3) (global estimated flops for the elimination after
factorization): 2.73979e+09
(RINFOG(12) RINFOG(13))*2^INFOG(34) (determinant):
(0.,0.)*(2^0)
INFOG(3) (estimated real workspace for factors on all
processors after analysis): 8377336
INFOG(4) (estimated integer workspace for factors on all
processors after analysis): 447902
INFOG(5) (estimated maximum front size in the complete
tree): 990
INFOG(6) (number of nodes in the complete tree): 2730
INFOG(7) (ordering option effectively use after analysis):
5
INFOG(8) (structural symmetry in percent of the permuted
matrix after analysis): 100
INFOG(9) (total real/complex workspace to store the matrix
factors after factorization): 8377336
INFOG(10) (total integer space store the matrix factors
after factorization): 447902
INFOG(11) (order of largest frontal matrix after
factorization): 990
INFOG(12) (number of off-diagonal pivots): 10
INFOG(13) (number of delayed pivots after factorization): 0
INFOG(14) (number of memory compress after factorization):
0
INFOG(15) (number of steps of iterative refinement after
solution): 0
INFOG(16) (estimated size (in MB) of all MUMPS internal
data for factorization after analysis: value on the most memory consuming
processor): 94
INFOG(17) (estimated size of all MUMPS internal data for
factorization after analysis: sum over all processors): 94
INFOG(18) (size of all MUMPS internal data allocated during
factorization: value on the most memory consuming processor): 94
INFOG(19) (size of all MUMPS internal data allocated during
factorization: sum over all processors): 94
INFOG(20) (estimated number of entries in the factors):
7080060
INFOG(21) (size in MB of memory effectively used during
factorization - value on the most memory consuming processor): 80
INFOG(22) (size in MB of memory effectively used during
factorization - sum over all processors): 80
INFOG(23) (after analysis: value of ICNTL(6) effectively
used): 0
INFOG(24) (after analysis: value of ICNTL(12) effectively
used): 1
INFOG(25) (after factorization: number of pivots modified
by static pivoting): 0
INFOG(28) (after factorization: number of null pivots
encountered): 0
INFOG(29) (after factorization: effective number of entries
in the factors (sum over all processors)): 7080060
INFOG(30, 31) (after solution: size in Mbytes of memory
used during solution phase): 92, 92
INFOG(32) (after analysis: type of analysis done): 1
INFOG(33) (value used for ICNTL(8)): 7
INFOG(34) (exponent of the determinant if determinant is
requested): 0
INFOG(35) (after factorization: number of entries taking
into account BLR factor compression - sum over all processors): 7080060
INFOG(36) (after analysis: estimated size of all MUMPS
internal data for running BLR in-core - value on the most memory consuming
processor): 0
INFOG(37) (after analysis: estimated size of all MUMPS
internal data for running BLR in-core - sum over all processors): 0
INFOG(38) (after analysis: estimated size of all MUMPS
internal data for running BLR out-of-core - value on the most memory
consuming processor): 0
INFOG(39) (after analysis: estimated size of all MUMPS
internal data for running BLR out-of-core - sum over all processors): 0
linear system matrix = precond matrix:
Mat Object: 1 MPI processes
type: seqaij
rows=38154, cols=38154
total: nonzeros=973446, allocated nonzeros=973446
total number of mallocs used during MatSetValues calls=0
not using I-node routines
[0]PETSC ERROR: --------------------- Error Message
--------------------------------------------------------------
[0]PETSC ERROR:
[0]PETSC ERROR: TSStep has failed due to DIVERGED_NONLINEAR_SOLVE, increase
-ts_max_snes_failures or make negative to attempt recovery
[0]PETSC ERROR: See https://www.mcs.anl.gov/petsc/documentation/faq.html
for trouble shooting.
[0]PETSC ERROR: Petsc Release Version 3.12.3, Jan, 03, 2020
Thanks,
Ashish
Scientific Computing Division
OnScale
CA, USA
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