test cases for GMRES and CG

[Yipkei Kwok]

Hi,

Question 1: Test case results for GMRES, one of the Krylov Subspace 
Methods, do not match the standard results.
Question 2: Where can I found test cases for CG, another Krylov Subspace 
Method?

[Question 1: Test case results for GMRES, one of the Krylov Subspace 
Methods, do not match the standard results.]
I have installed PETSc 2.3.3 on an Itanium 2 machine.

Then, I tried to verify the correctness of the installation by running 
test cases in the following directory.
src/ksp/ksp/examples/tests

I got the following error when running example 17
$ make runex17
17c17
<  16 KSP Residual norm 4.19038e-08
---
 >  16 KSP Residual norm 2.9736e-07
29c29
<     type=aij, rows=36, cols=36
---
 >     type=seqaij, rows=36, cols=36
32c32
< Norm of error 9.90874e-10, Iterations 16
---
 > Norm of error 7.03149e-09,Iterations 16
Possible problem with ex17_1, diffs above





And, I got the following error when running the example 19.
$ make runex19
3,21c3,22
<   0 KSP Residual norm 2.34801
<   1 KSP Residual norm 1.10991
<   2 KSP Residual norm 0.905352
<   3 KSP Residual norm 0.719343
<   4 KSP Residual norm 0.542882
<   5 KSP Residual norm 0.378135
<   6 KSP Residual norm 0.2063
<   7 KSP Residual norm 0.0785186
<   8 KSP Residual norm 0.0271851
<   9 KSP Residual norm 0.0154188
<  10 KSP Residual norm 0.00984534
<  11 KSP Residual norm 0.00604218
<  12 KSP Residual norm 0.00189778
<  13 KSP Residual norm 0.000708898
<  14 KSP Residual norm 0.000230128
<  15 KSP Residual norm 9.31276e-05
<  16 KSP Residual norm 3.83561e-05
<  17 KSP Residual norm 2.04223e-05
< Number of iterations = 17
---
 >   0 KSP Residual norm 2.90126
 >   1 KSP Residual norm 1.45832
 >   2 KSP Residual norm 1.18005
 >   3 KSP Residual norm 0.941127
 >   4 KSP Residual norm 0.696937
 >   5 KSP Residual norm 0.484776
 >   6 KSP Residual norm 0.245944
 >   7 KSP Residual norm 0.102339
 >   8 KSP Residual norm 0.0501583
 >   9 KSP Residual norm 0.0346147
 >  10 KSP Residual norm 0.0196042
 >  11 KSP Residual norm 0.0102261
 >  12 KSP Residual norm 0.00331366
 >  13 KSP Residual norm 0.00153735
 >  14 KSP Residual norm 0.000698171
 >  15 KSP Residual norm 0.000356882
 >  16 KSP Residual norm 0.000136588
 >  17 KSP Residual norm 5.23453e-05
 >  18 KSP Residual norm 1.50308e-05
 > Number of iterations = 18
Possible problem with ex19_1, diffs above

Does anyone have a clue why the results are different?

Note that I also have PETSc installed on a Xeon machine. The results 
generated on the Xeon match the results generated on the Itanium 2 
machine for ex19. But, for ex17, the results generated on the Xeon 
machine match neither the standard results nor the results generated on 
the Itanium 2 machine.






[Question 2: Where can I find test cases for CG, another Krylov Subspace 
Method?]

ex17 and ex19 in the src/ksp/ksp/examples/tests directory are using the 
GMRES method. We want to make sure that the CG method is working 
correctly. The option `-ksp_type cg' does not appear in any test case of 
that directory. Where can I find test cases for CG? Or, is there anyway 
that I can verify the correctness of the CG installation?



[Extra information]
Here is the machine configuration.
Four Intel Itanium 2 processor
8GB memory
Red Hat Enterprise Linux AS release 4 (Nahant Update 5)
gcc 3.4.6
gfortran 4.1.1
PETSc Configure Options: --with-mpi=0 --prefix=/usr/local/EE/ --with-x=0 
--with-x11=0
-download-c-blas-lapack=ifneeded -download-f-blas-lapack=ifneeded 
--with-shared=
0 --with-scalar-type=complex --configModules=PETSc.Configure 
--optionsModule=PETSc.compilerOptions

Please note that the option `--with-mpi=0' is used as we want a 
sequential version of PETSc.



Thank you very much!

Regards,
Yipkei

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********************************************
Yipkei Kwok
Ph.D. Student
Research Assistant
HiPerSys Lab
Department of Computer Science
The University of Texas at El Paso
Phone: 915 747 6433 (O)
E-mail: ykwok2 at miners dot utep dot edu
********************************************