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<DIV><FONT size=2>Hi, </FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2>SNES does not converge. After I tested following FAQ
hints but still could not find a reason.</FONT></DIV>
<DIV><FONT size=2>Could you please refer to the following THREE outputs to give
me some hints.</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2>================OUTPUT 1=============</FONT></DIV>
<DIV><FONT size=2>C:\cygwin\home\rabbit\pGFEM-test>pgfem -info<BR>[0]
PetscInitialize(): PETSc successfully started: number of processors = 1<BR>[0]
PetscGetHostName(): Rejecting domainname, likely is NIS RTI458-LAPTOP=(?.<BR>[0]
PetscInitialize(): Running on machine: RTI458-LAPTOP<BR>[0]
PetscCommDuplicate(): Duplicating a communicator 1140850688 -2080374784
max<BR>tags = 2147483647<BR>[0] PetscCommDuplicate(): returning tag
2147483647<BR>[0] PetscCommDuplicate(): Using internal PETSc communicator
1140850688 -20803747<BR>84<BR>[0] PetscCommDuplicate(): returning
tag 2147483646<BR>[0] PetscCommDuplicate(): Using internal PETSc communicator
1140850688 -20803747<BR>84<BR>[0] PetscCommDuplicate(): returning
tag 2147483645<BR>[0] PetscCommDuplicate(): Using internal PETSc communicator
1140850688 -20803747<BR>84<BR>[0] PetscCommDuplicate(): returning
tag 2147483644<BR>[0] PetscCommDuplicate(): returning tag
2147483643<BR>[0] PetscCommDuplicate(): returning tag
2147483642<BR>[0] PetscCommDuplicate(): Using internal PETSc communicator
1140850688 -20803747<BR>84<BR>[0] PetscCommDuplicate(): returning
tag 2147483641<BR>atol=1e-050, rtol=1e-008, stol=1e-008, maxit=50,
maxf=10000<BR>[0] PetscCommDuplicate(): returning tag
2147483640<BR>[0] PetscCommDuplicate(): returning tag
2147483639<BR>[0] PetscCommDuplicate(): returning tag
2147483638<BR>[0] PetscCommDuplicate(): returning tag
2147483637<BR>[0] MatSetUpPreallocation(): Warning not preallocating matrix
storage<BR>[0] MatAssemblyEnd_SeqAIJ(): Matrix size: 24 X 24; storage space: 264
unneeded,5<BR>76 used<BR>[0] MatAssemblyEnd_SeqAIJ(): Number of mallocs during
MatSetValues() is 48<BR>[0] MatAssemblyEnd_SeqAIJ(): Maximum nonzeros in any row
is 24<BR>[0] Mat_CheckInode(): Found 5 nodes of 24. Limit used: 5. Using Inode
routines<BR>[0] MatAssemblyEnd_SeqAIJ(): Matrix size: 24 X 24; storage space:
184 unneeded,3<BR>92 used<BR>[0] MatAssemblyEnd_SeqAIJ(): Number of mallocs
during MatSetValues() is 0<BR>[0] MatAssemblyEnd_SeqAIJ(): Maximum nonzeros in
any row is 24<BR>[0] Mat_CheckInode(): Found 15 nodes of 24. Limit used: 5.
Using Inode routines<BR>[0] PetscCommDuplicate(): returning tag
2147483636<BR>[0] PetscCommDuplicate(): returning tag
2147483635<BR>[0] PetscCommDuplicate(): returning tag
2147483634<BR>[0] PetscCommDuplicate(): returning tag
2147483633<BR>[0] PetscCommDuplicate(): returning tag
2147483632<BR>[0] PCSetUp(): Setting up new PC<BR>[0] PetscCommDuplicate():
Duplicating a communicator 1140850689 -2080374783 max<BR>tags =
2147483647<BR>[0] PetscCommDuplicate(): returning tag
2147483647<BR>[0] PetscCommDuplicate(): Using internal PETSc communicator
1140850689 -20803747<BR>83<BR>[0] PetscCommDuplicate(): returning
tag 2147483646<BR>[0] PetscCommDuplicate(): Using internal PETSc communicator
1140850689 -20803747<BR>83<BR>[0] PetscCommDuplicate(): returning
tag 2147483645<BR>[0] PetscCommDuplicate(): Using internal PETSc communicator
1140850689 -20803747<BR>83<BR>[0] PetscCommDuplicate(): returning
tag 2147483644<BR>[0] PetscCommDuplicate(): Using internal PETSc communicator
1140850689 -20803747<BR>83<BR>[0] PetscCommDuplicate(): returning
tag 2147483643<BR>[0] PetscCommDuplicate(): returning tag
2147483631<BR>[0] KSPDefaultConverged(): Linear solver has converged. Residual
norm 6.43598e-0<BR>08 is less than relative tolerance 1e-005 times initial right
hand side norm 0.0<BR>984377 at iteration 1<BR>[0] SNESSolve_LS(): iter=0,
linear solve iterations=1<BR>[0] SNESLSCheckResidual_Private():
||J^T(F-Ax)||/||F-AX|| 4.72897e+006 near zero<BR> implies inconsistent
rhs<BR>[0] SNESLineSearchCubic(): Cubic step no good, shrinking lambda,
lambda=5.00000<BR>00000000003e-002<BR>[0] SNESLineSearchCubic(): Cubic step no
good, shrinking lambda, lambda=2.23337<BR>96462448683e-002<BR>[0]
SNESLineSearchCubic(): Cubic step no good, shrinking lambda,
lambda=1.05579<BR>95926265388e-002<BR>[0] SNESLineSearchCubic(): Cubically
determined step, lambda=5.2789979631326939e<BR>-003<BR>[0] SNESSolve_LS():
fnorm=7.0710677904340784e+000, gnorm=7.0372413153730617e+000<BR>,
ynorm=9.8437692875833122e-002, lssucceed=1<BR>[0] MatAssemblyEnd_SeqAIJ():
Matrix size: 24 X 24; storage space: 56 unneeded,57<BR>6 used<BR>[0]
MatAssemblyEnd_SeqAIJ(): Number of mallocs during MatSetValues() is 16<BR>[0]
MatAssemblyEnd_SeqAIJ(): Maximum nonzeros in any row is 24<BR>[0]
Mat_CheckInode(): Found 5 nodes of 24. Limit used: 5. Using Inode
routines<BR>[0] MatAssemblyEnd_SeqAIJ(): Matrix size: 24 X 24; storage space:
184 unneeded,3<BR>92 used<BR>[0] MatAssemblyEnd_SeqAIJ(): Number of mallocs
during MatSetValues() is 0<BR>[0] MatAssemblyEnd_SeqAIJ(): Maximum nonzeros in
any row is 24<BR>[0] Mat_CheckInode(): Found 15 nodes of 24. Limit used: 5.
Using Inode routines<BR>[0] PCSetUp(): Setting up PC with same nonzero
pattern<BR>[0] KSPDefaultConverged(): Linear solver has converged. Residual norm
3.06534e-0<BR>08 is less than relative tolerance 1e-005 times initial right hand
side norm 0.0<BR>979013 at iteration 1<BR>[0] SNESSolve_LS(): iter=1, linear
solve iterations=1<BR>[0] SNESLSCheckResidual_Private(): ||J^T(F-Ax)||/||F-AX||
3.89599e+006 near zero<BR> implies inconsistent rhs<BR>[0]
SNESLineSearchCubic(): Cubic step no good, shrinking lambda,
lambda=5.00000<BR>00000000003e-002<BR>[0] SNESLineSearchCubic(): Cubic step no
good, shrinking lambda, lambda=2.04981<BR>30512175090e-002<BR>[0]
SNESLineSearchCubic(): Cubic step no good, shrinking lambda,
lambda=7.90835<BR>12647314651e-003<BR>[0] SNESLineSearchCubic(): Cubic step no
good, shrinking lambda, lambda=1.64025<BR>15420099921e-003<BR>[0]
SNESLineSearchCubic(): Cubic step no good, shrinking lambda,
lambda=1.64025<BR>15420099923e-004<BR>[0] SNESLineSearchCubic(): Cubic step no
good, shrinking lambda, lambda=2.40360<BR>10928094253e-005<BR>[0]
SNESLineSearchCubic(): Cubic step no good, shrinking lambda,
lambda=3.57264<BR>27106588782e-006<BR>[0] SNESLineSearchCubic(): Cubic step no
good, shrinking lambda, lambda=5.33322<BR>51840976446e-007<BR>[0]
SNESLineSearchCubic(): Cubic step no good, shrinking lambda,
lambda=7.91785<BR>19721784329e-008<BR>[0] SNESLineSearchCubic(): Cubic step no
good, shrinking lambda, lambda=1.14184<BR>37592725693e-008<BR>[0]
SNESLineSearchCubic(): Cubic step no good, shrinking lambda,
lambda=1.41828<BR>88220817760e-009<BR>[0] SNESLineSearchCubic(): Cubic step no
good, shrinking lambda, lambda=1.41828<BR>88220817761e-010<BR>[0]
SNESLineSearchCubic(): Cubic step no good, shrinking lambda,
lambda=1.41828<BR>88220817761e-011<BR>[0] SNESLineSearchCubic(): Cubic step no
good, shrinking lambda, lambda=1.41828<BR>88220817762e-012<BR>[0]
SNESLineSearchCubic(): Cubic step no good, shrinking lambda,
lambda=1.41828<BR>88220817764e-013<BR>[0] SNESLineSearchCubic(): Cubic step no
good, shrinking lambda, lambda=1.41828<BR>88220817765e-014<BR>[0]
SNESLineSearchCubic(): Cubic step no good, shrinking lambda,
lambda=1.41828<BR>88220817765e-015<BR>[0] SNESLineSearchCubic(): Unable to find
good step length! 18<BR>[0] SNESLineSearchCubic():
fnorm=7.0372413153730617e+000, gnorm=7.03724146468665<BR>79e+000,
ynorm=9.7901291669040949e-002, lambda=1.4182888220817765e-015,
initial<BR>slope=-4.9522772347319197e+001<BR>[0] SNESSolve_LS():
fnorm=7.0372413153730617e+000, gnorm=7.0372414646866579e+000<BR>,
ynorm=9.7901291669040949e-002, lssucceed=0<BR>[0] SNESLSCheckLocalMin_Private():
|| J^T F|| 3.8948e+006 near zero implies foun<BR>d a local minimum<BR>STEP 0
(Newton iterations: 2)</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2>diverged reason: DIVERGED_LS_FAILURE<BR>[0] Petsc_DelComm():
Deleting PETSc communicator imbedded in a user MPI_Comm 114<BR>0850689<BR>[0]
PetscCommDestroy(): Deleting PETSc MPI_Comm -2080374783<BR>[0] Petsc_DelComm():
Deleting PETSc communicator imbedded in a user MPI_Comm -20<BR>80374783<BR>[0]
Petsc_DelTag(): Deleting tag data in an MPI_Comm -2080374783</FONT></DIV>
<DIV> </DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2>===============OUTPUT 2==================</FONT></DIV>
<DIV><FONT size=2>C:\cygwin\home\rabbit\pGFEM-test>pgfem -snes_type
test<BR>atol=1e-050, rtol=1e-008, stol=1e-008, maxit=50, maxf=10000<BR>Testing
hand-coded Jacobian, if the ratio is<BR>O(1.e-8), the hand-coded Jacobian is
probably correct.<BR>Run with -snes_test_display to show difference<BR>of
hand-coded and finite difference Jacobian.<BR>Norm of matrix ratio 5.91627e-007
difference 23.5238<BR>Norm of matrix ratio 2.1444e-007 difference
8.52641<BR>Norm of matrix ratio 2.49179e-007 difference 9.90765<BR>[0]PETSC
ERROR: SNESSolve() line 1871 in
src/snes/interface/C:\cygwin\home\PETSC<BR>-~1.3-P\src\snes\INTERF~1\snes.c<BR>[0]PETSC
ERROR: User provided function() line 302 in
unknowndirectory/c:\cygwin\<BR>home\rabbit\pgfem - csrbf\domain.cpp<BR>[0]PETSC
ERROR: User provided function() line 34 in
unknowndirectory/c:\cygwin\h<BR>ome\rabbit\pgfem - csrbf\main.cpp</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2>=================OUTPUT 3===============</FONT></DIV>
<DIV><FONT size=2>C:\cygwin\home\rabbit\pGFEM-test>pgfem -snes_mf_operator
-ksp_monitor_true_residual</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2>.......</FONT></DIV>
<DIV><FONT size=2> 0 KSP preconditioned resid norm 1.393538348796e-001 true
resid norm 7.81673715<BR>5471e-001 ||Ae||/||Ax|| 1.000000000000e+000<BR> 1
KSP preconditioned resid norm 8.503891307640e-002 true resid norm
9.78452660<BR>6728e-001 ||Ae||/||Ax|| 1.251740516806e+000<BR> 2 KSP
preconditioned resid norm 2.769264336444e-005 true resid norm
3.06983248<BR>7178e+001 ||Ae||/||Ax|| 3.927255613334e+001<BR> 3 KSP
preconditioned resid norm 2.140259007162e-005 true resid norm
3.58014377<BR>1001e+001 ||Ae||/||Ax|| 4.580099982632e+001<BR> 4 KSP
preconditioned resid norm 3.271042954922e-006 true resid norm
3.39507468<BR>5413e+000 ||Ae||/||Ax|| 4.343339961273e+000<BR> 5 KSP
preconditioned resid norm 8.052808588169e-009 true resid norm
5.12770240<BR>1411e-002 ||Ae||/||Ax|| 6.559901272645e-002<BR> 29 SNES
Function norm 7.688867566940e-001<BR> ........</FONT></DIV>
<DIV><FONT size=2> 0 KSP preconditioned resid norm 9.650772260845e-002
true resid norm 6.46872347<BR>8452e-001 ||Ae||/||Ax||
1.000000000000e+000<BR> 1 KSP preconditioned resid norm
8.382067825597e-002 true resid norm 8.95465886<BR>5836e-001 ||Ae||/||Ax||
1.384300765934e+000<BR> 2 KSP preconditioned resid norm
2.770083563275e-005 true resid norm 4.75963661<BR>5364e+001 ||Ae||/||Ax||
7.357922519363e+001<BR> 3 KSP preconditioned resid norm
1.746905778563e-005 true resid norm 5.65561314<BR>8780e+001 ||Ae||/||Ax||
8.743012694265e+001<BR> 4 KSP preconditioned resid norm
2.595985260271e-006 true resid norm 4.85638048<BR>7409e+000 ||Ae||/||Ax||
7.507478876761e+000<BR> 5 KSP preconditioned resid norm
1.791711722028e-007 true resid norm 6.13620207<BR>0783e-002 ||Ae||/||Ax||
9.485955136624e-002<BR> 50 SNES Function norm 6.449968664911e-001<BR>STEP 0
(Newton iterations: 50)</FONT></DIV>
<DIV> </DIV>
<DIV><FONT size=2>diverged reason: DIVERGED_MAX_IT</FONT></DIV>
<DIV> </DIV>
<DIV><FONT
size=2>C:\cygwin\home\rabbit\pGFEM-test></FONT></DIV></BODY></HTML>