[petsc-users] What could be the reason for a convergence history like this one?

(Rebecca) Xuefei YUAN xy2102 at columbia.edu
Tue Feb 9 12:39:25 CST 2010 

Dear Matt,
There is no analytic Jacobian in this code, and the history in the  
last thread was from -snes_mf(50 SNES Function norm  
1.282754274487e-04). if I change this -snes_mf to  
-dmmg_jacobian_mf_fd(50 SNES Function norm 1.251867110549e-04), it  
seems could go farther, but after some iterations, the residual stops  
decreasing and becomes increasing again:

   0 SNES Function norm 1.489006328086e+00
   1 SNES Function norm 1.043276646550e-01
   2 SNES Function norm 2.647531016073e-02
   3 SNES Function norm 5.726158789720e-03
   4 SNES Function norm 2.497853960325e-03
   5 SNES Function norm 5.178505521812e-04
   6 SNES Function norm 4.161124880646e-04
   7 SNES Function norm 3.063079764249e-04
   8 SNES Function norm 2.216203245831e-04
   9 SNES Function norm 1.346446389755e-04
  10 SNES Function norm 1.298929693823e-04
  11 SNES Function norm 1.296352502362e-04
  12 SNES Function norm 1.294010890218e-04
  13 SNES Function norm 1.293158188978e-04
  14 SNES Function norm 1.292537899035e-04
  15 SNES Function norm 1.291882769093e-04
  16 SNES Function norm 1.290900941440e-04
  17 SNES Function norm 1.290650500805e-04
  18 SNES Function norm 1.290064396106e-04
  19 SNES Function norm 1.288121780049e-04
  20 SNES Function norm 1.286415872476e-04
  21 SNES Function norm 1.285583242966e-04
  22 SNES Function norm 1.284369816260e-04
  23 SNES Function norm 1.283315973569e-04
  24 SNES Function norm 1.279868505371e-04
  25 SNES Function norm 1.275988479887e-04
  26 SNES Function norm 1.274802192747e-04
  27 SNES Function norm 1.273256834679e-04
  28 SNES Function norm 1.272894071688e-04
  29 SNES Function norm 1.272080215426e-04
  30 SNES Function norm 1.271850575230e-04
  31 SNES Function norm 1.271715499728e-04
  32 SNES Function norm 1.270966212068e-04
  33 SNES Function norm 1.270621146091e-04
  34 SNES Function norm 1.269027315361e-04
  35 SNES Function norm 1.267506000983e-04
  36 SNES Function norm 1.266693862935e-04
  37 SNES Function norm 1.265241359123e-04
  38 SNES Function norm 1.264402076307e-04
  39 SNES Function norm 1.263630732412e-04
  40 SNES Function norm 1.263228374417e-04
  41 SNES Function norm 1.262265153181e-04
  42 SNES Function norm 1.261886787880e-04
  43 SNES Function norm 1.261879329103e-04
  44 SNES Function norm 1.261838619067e-04
  45 SNES Function norm 1.261818759514e-04
  46 SNES Function norm 1.261810379326e-04
  47 SNES Function norm 1.261795964495e-04
  48 SNES Function norm 1.261780785438e-04
  49 SNES Function norm 1.261775208833e-04
  50 SNES Function norm 1.261774151048e-04
Nonlinear solve did not converge due to DIVERGED_MAX_IT
rebecca at YuanWork:~/linux/code/twoway/twmgvggt/test/comp_oreggt6_twmgvggtnivex$  
./oreggt6.exe -options_file option_oreggt6 -loadbin
   0 SNES Function norm 1.261774151048e-04
   1 SNES Function norm 1.261771432171e-04
   2 SNES Function norm 1.261763069424e-04
   3 SNES Function norm 1.261720612263e-04
   4 SNES Function norm 1.261404001592e-04
   5 SNES Function norm 1.260149619260e-04
   6 SNES Function norm 1.256432398293e-04
   7 SNES Function norm 1.253451015765e-04
   8 SNES Function norm 1.253182414538e-04
   9 SNES Function norm 1.252819131702e-04
  10 SNES Function norm 1.252738755369e-04
  11 SNES Function norm 1.252632764516e-04
  12 SNES Function norm 1.252566042921e-04
  13 SNES Function norm 1.252526838492e-04
  14 SNES Function norm 1.252485483438e-04
  15 SNES Function norm 1.252449709435e-04
  16 SNES Function norm 1.252416675394e-04
  17 SNES Function norm 1.252362756882e-04
  18 SNES Function norm 1.252324330089e-04
  19 SNES Function norm 1.251957972997e-04
  20 SNES Function norm 1.251926714223e-04
  21 SNES Function norm 1.251912297445e-04
  22 SNES Function norm 1.251910026775e-04
  23 SNES Function norm 1.251903079400e-04
  24 SNES Function norm 1.251897130474e-04
  25 SNES Function norm 1.251890057526e-04
  26 SNES Function norm 1.251886739317e-04
  27 SNES Function norm 1.251886214966e-04
  28 SNES Function norm 1.251883802081e-04
  29 SNES Function norm 1.251883374146e-04
  30 SNES Function norm 1.251880140622e-04
  31 SNES Function norm 1.251876765348e-04
  32 SNES Function norm 1.251876758034e-04
  33 SNES Function norm 1.251875904308e-04
  34 SNES Function norm 1.251874566739e-04
  35 SNES Function norm 1.251867963213e-04
  36 SNES Function norm 1.251867110525e-04
  37 SNES Function norm 1.251867110526e-04
  38 SNES Function norm 1.251867110526e-04
  39 SNES Function norm 1.251867110526e-04
  40 SNES Function norm 1.251867110527e-04
  41 SNES Function norm 1.251867110527e-04
  42 SNES Function norm 1.251867110527e-04
  43 SNES Function norm 1.251867110528e-04
  44 SNES Function norm 1.251867110528e-04
  45 SNES Function norm 1.251867110528e-04
  46 SNES Function norm 1.251867110529e-04
  47 SNES Function norm 1.251867110529e-04
  48 SNES Function norm 1.251867110530e-04
  49 SNES Function norm 1.251867110530e-04
  50 SNES Function norm 1.251867110530e-04
Nonlinear solve did not converge due to DIVERGED_MAX_IT
rebecca at YuanWork:~/linux/code/twoway/twmgvggt/test/comp_oreggt6_twmgvggtnivex$  
./oreggt6.exe -options_file option_oreggt6 -loadbin
   0 SNES Function norm 1.251867110530e-04
   1 SNES Function norm 1.251867110531e-04
   2 SNES Function norm 1.251867110531e-04
   3 SNES Function norm 1.251867110532e-04
   4 SNES Function norm 1.251867110532e-04
   5 SNES Function norm 1.251867110532e-04
   6 SNES Function norm 1.251867110533e-04
   7 SNES Function norm 1.251867110533e-04
   8 SNES Function norm 1.251867110534e-04
   9 SNES Function norm 1.251867110533e-04
  10 SNES Function norm 1.251867110534e-04
  11 SNES Function norm 1.251867110534e-04
  12 SNES Function norm 1.251867110535e-04
  13 SNES Function norm 1.251867110535e-04
  14 SNES Function norm 1.251867110536e-04
  15 SNES Function norm 1.251867110536e-04
  16 SNES Function norm 1.251867110536e-04
  17 SNES Function norm 1.251867110537e-04
  18 SNES Function norm 1.251867110537e-04
  19 SNES Function norm 1.251867110538e-04
  20 SNES Function norm 1.251867110538e-04
  21 SNES Function norm 1.251867110539e-04
  22 SNES Function norm 1.251867110539e-04
  23 SNES Function norm 1.251867110539e-04
  24 SNES Function norm 1.251867110539e-04
  25 SNES Function norm 1.251867110540e-04
  26 SNES Function norm 1.251867110540e-04
  27 SNES Function norm 1.251867110541e-04
  28 SNES Function norm 1.251867110541e-04
  29 SNES Function norm 1.251867110541e-04
  30 SNES Function norm 1.251867110541e-04
  31 SNES Function norm 1.251867110542e-04
  32 SNES Function norm 1.251867110542e-04
  33 SNES Function norm 1.251867110543e-04
  34 SNES Function norm 1.251867110543e-04
  35 SNES Function norm 1.251867110544e-04
  36 SNES Function norm 1.251867110544e-04
  37 SNES Function norm 1.251867110545e-04
  38 SNES Function norm 1.251867110545e-04
  39 SNES Function norm 1.251867110545e-04
  40 SNES Function norm 1.251867110546e-04
  41 SNES Function norm 1.251867110546e-04
  42 SNES Function norm 1.251867110546e-04
  43 SNES Function norm 1.251867110547e-04
  44 SNES Function norm 1.251867110547e-04
  45 SNES Function norm 1.251867110548e-04
  46 SNES Function norm 1.251867110548e-04
  47 SNES Function norm 1.251867110548e-04
  48 SNES Function norm 1.251867110548e-04
  49 SNES Function norm 1.251867110549e-04
  50 SNES Function norm 1.251867110549e-04
Nonlinear solve did not converge due to DIVERGED_MAX_IT



Quoting Matthew Knepley <knepley at gmail.com>:

> Did you try checking your Jacobian using -snes_mf?
>
>    Matt
>
> On Tue, Feb 9, 2010 at 12:21 PM, (Rebecca) Xuefei YUAN
> <xy2102 at columbia.edu>wrote:
>
>> Hi,
>>
>> The SNES convergence history shows the residual increases or stop
>> decreasing starting at some iteration. I ran two different cases for the
>> same code, and the history looks similar, what could be wrong with the code?
>>
>> Thanks very much!
>>
>> Case 1:
>>  0 SNES Function norm 9.593111354483e-01
>>  1 SNES Function norm 1.233321371555e-01
>>  2 SNES Function norm 2.926382110614e-02
>>  3 SNES Function norm 2.091318748212e-02
>>  4 SNES Function norm 1.047907743570e-02
>>  5 SNES Function norm 4.462043675959e-03
>>  6 SNES Function norm 1.851050848655e-03
>>  7 SNES Function norm 4.417550480988e-04
>>  8 SNES Function norm 1.736388356513e-04
>>  9 SNES Function norm 6.300414578098e-05
>>  10 SNES Function norm 1.929829710585e-05
>>  11 SNES Function norm 1.506367625001e-05
>>  12 SNES Function norm 1.480567720594e-05
>>  13 SNES Function norm 1.470754287980e-05
>>  14 SNES Function norm 1.461728595512e-05
>>  15 SNES Function norm 1.453616609384e-05
>>  16 SNES Function norm 1.441040320141e-05
>>  17 SNES Function norm 1.402352953635e-05
>>  18 SNES Function norm 1.343005745899e-05
>>  19 SNES Function norm 1.328043697395e-05
>>  20 SNES Function norm 1.327501784736e-05
>>  21 SNES Function norm 1.327431008405e-05
>>  22 SNES Function norm 1.327343169426e-05
>>  23 SNES Function norm 1.327273768560e-05
>>  24 SNES Function norm 1.327185496127e-05
>>  25 SNES Function norm 1.327119625499e-05
>>  26 SNES Function norm 1.327071509157e-05
>>  27 SNES Function norm 1.327038695378e-05
>>  28 SNES Function norm 1.326990549326e-05
>>  29 SNES Function norm 1.326917602672e-05
>>  30 SNES Function norm 1.326830723835e-05
>>  31 SNES Function norm 1.326796002362e-05
>>  32 SNES Function norm 1.326777827731e-05
>>  33 SNES Function norm 1.326755622116e-05
>>  34 SNES Function norm 1.326732752144e-05
>>  35 SNES Function norm 1.326698050145e-05
>>  36 SNES Function norm 1.326640877572e-05
>>  37 SNES Function norm 1.326587074902e-05
>>  38 SNES Function norm 1.326573931166e-05
>>  39 SNES Function norm 1.326564241601e-05
>>  40 SNES Function norm 1.326548432075e-05
>>  41 SNES Function norm 1.326531590041e-05
>>  42 SNES Function norm 1.326531590043e-05
>>  43 SNES Function norm 1.326531590045e-05
>>  44 SNES Function norm 1.326531590044e-05
>>  45 SNES Function norm 1.326531590044e-05
>>  46 SNES Function norm 1.326531590043e-05
>>  47 SNES Function norm 1.326531590045e-05
>>  48 SNES Function norm 1.326531590044e-05
>>  49 SNES Function norm 1.326531590046e-05
>>  50 SNES Function norm 1.326531590046e-05
>> Nonlinear solve did not converge due to DIVERGED_MAX_IT
>>
>> case 2:
>>  0 SNES Function norm 1.489006328086e+00
>>  1 SNES Function norm 1.044141602147e-01
>>  2 SNES Function norm 2.662563646189e-02
>>  3 SNES Function norm 5.764005178654e-03
>>  4 SNES Function norm 2.493444656346e-03
>>  5 SNES Function norm 5.180475798178e-04
>>  6 SNES Function norm 4.166251801170e-04
>>  7 SNES Function norm 3.066582000814e-04
>>  8 SNES Function norm 2.189666367666e-04
>>  9 SNES Function norm 1.354684191244e-04
>>  10 SNES Function norm 1.287520392923e-04
>>  11 SNES Function norm 1.286080621054e-04
>>  12 SNES Function norm 1.285437650356e-04
>>  13 SNES Function norm 1.284168806812e-04
>>  14 SNES Function norm 1.283833115348e-04
>>  15 SNES Function norm 1.283700090330e-04
>>  16 SNES Function norm 1.283691578788e-04
>>  17 SNES Function norm 1.283486627334e-04
>>  18 SNES Function norm 1.283349991927e-04
>>  19 SNES Function norm 1.283332060308e-04
>>  20 SNES Function norm 1.283026682165e-04
>>  21 SNES Function norm 1.282981662835e-04
>>  22 SNES Function norm 1.282944044720e-04
>>  23 SNES Function norm 1.282831861627e-04
>>  24 SNES Function norm 1.282754274487e-04
>>  25 SNES Function norm 1.282754274487e-04
>>  26 SNES Function norm 1.282754274487e-04
>>  27 SNES Function norm 1.282754274487e-04
>>  28 SNES Function norm 1.282754274487e-04
>>  29 SNES Function norm 1.282754274487e-04
>>  30 SNES Function norm 1.282754274487e-04
>>  31 SNES Function norm 1.282754274487e-04
>>  32 SNES Function norm 1.282754274487e-04
>>  33 SNES Function norm 1.282754274487e-04
>>  34 SNES Function norm 1.282754274487e-04
>>  35 SNES Function norm 1.282754274487e-04
>>  36 SNES Function norm 1.282754274487e-04
>>  37 SNES Function norm 1.282754274487e-04
>>  38 SNES Function norm 1.282754274487e-04
>>  39 SNES Function norm 1.282754274487e-04
>>  40 SNES Function norm 1.282754274487e-04
>>  41 SNES Function norm 1.282754274487e-04
>>  42 SNES Function norm 1.282754274487e-04
>>  43 SNES Function norm 1.282754274487e-04
>>  44 SNES Function norm 1.282754274487e-04
>>  45 SNES Function norm 1.282754274487e-04
>>  46 SNES Function norm 1.282754274487e-04
>>  47 SNES Function norm 1.282754274487e-04
>>  48 SNES Function norm 1.282754274487e-04
>>  49 SNES Function norm 1.282754274487e-04
>>  50 SNES Function norm 1.282754274487e-04
>>
>> Thanks a lot!
>>
>> --
>> (Rebecca) Xuefei YUAN
>> Department of Applied Physics and Applied Mathematics
>> Columbia University
>> Tel:917-399-8032
>> www.columbia.edu/~xy2102 <http://www.columbia.edu/%7Exy2102>
>>
>>
>
>
> --
> What most experimenters take for granted before they begin their experiments
> is infinitely more interesting than any results to which their experiments
> lead.
> -- Norbert Wiener
>



-- 
(Rebecca) Xuefei YUAN
Department of Applied Physics and Applied Mathematics
Columbia University
Tel:917-399-8032
www.columbia.edu/~xy2102

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