Reference Norm

[Roland]

Hi,
In many Elmer examples I see that often a "Reference Norm" is used for a given solver in the sif file. So my question is:
How must this "Reference Norm" instruction be used, meaning how is it possible to know the correct norm of a variable before having solved the sif file?
Thanks for any help!
Roland

[kevinarden]

You are supposed to know the reference norm when you set up a test case.

Consistency testing of solvers
Each solver may be tested for consistency. The way the testing is performed is that it is assumed that the
correct solution will have a predefined norm. After the simulation has been carried out the computed norm
and predefined norm are compared. If they are the same with a given tolerance the test is assumed to be
passed.
The result of a test is outputted on the screen. Additionally a file named TEST.PASSED is saved in
the working directory. If all the tests of the case are passed then the number 1 is written to the file in ascii
format. If any of the tests fails then the number 0 is written to the file, correspondingly.
Reference Norm Real
The target norm for the solver. The computed norm is tested against this one.
Reference Norm Tolerance Real
The tolerance for testing. The default is 1.0e-6. A sloppier tolerance could be used if the case is known
to be sensitive against numerical fluctuations.

[Roland]

Hi,
Thank you Kevin for your answer.
But then what happens if you give no reference norm for a solver? Will the TEST.PASSED file then automatically be filled with a 0 ?
Thanks in advance for your help.
Roland

[kevinarden]

I think if you do not give a reference norm, no check is made. and no file is created.

[Roland]

Thanks for your help!
Roland