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| − | =Adding a Test Case to a Thorn=
| + | sFwFGj <a href="http:// rvfyxonxuauz.com/"> rvfyxonxuauz</a>, [url=http:// bhinpgokofes.com/] bhinpgokofes[/url], [link=http:// bmgrpbgafrjw.com/] bmgrpbgafrjw[/link], http:// zfracgfrimzy.com/ |
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| − | This page describes how to add a test case to a Cactus thorn. It will
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| − | guide you step-by-step through the ideas behind test cases to some of
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| − | the finer details that make a test case easy to use.
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| − | | |
| − | sHrMI2 <a href="http:// kwteszcsbsiq.com/"> kwteszcsbsiq</a>, [url=http:// sanshpwrbnlr.com/] sanshpwrbnlr[/url], [link=http:// dngoaahxfvbk.com/] dngoaahxfvbk[/link], http:// brqfjiefbszv.com/ | |
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| − | ==How to create a test case==
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| − | It is probably best to start from a working parameter file that uses a
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| − | particular feature. Then one removes all those features and thorns
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| − | that are not necessary. To reduce the size further, one reduces the
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| − | number of time steps, chooses a much smaller domain and a much coarse
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| − | grid. It may make sense to introduce symmetries or periodic
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| − | boundaries.
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| − | | |
| − | Note that a test case does not need to provide physically interesting
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| − | output; it is only supposed to check whether the code still provides
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| − | the same output. Thus, as long as a coarser grid still executes the
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| − | same routines, it is fine. Of course, the grid must not be so coarse
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| − | that it generates nans.
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| − | | |
| − | At this stage, it may also make sense to avoid mesh refinement or
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| − | multi-block systems, or to reduce the order of accuracy.
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| − | In the end, the parameter file should run on a single core, should not
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| − | need more than a few hundred MByte of memory, and should finish in
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| − | under two minutes. Typically, it suffices to run for a few time steps
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| − | on a 10^3 domain.
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| − | At this stage, the physics output of the parameter file has probably
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| − | changed a lot. This is fine; all it needs to do is to check that the
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| − | feature that is to be tested will return the same result in the future
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| − | as it does now.
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| − | | |
| − | ==How to finish a test case==
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| − | After these steps, you should make a few more modifiations to the
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| − | parameter file.
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| − | Output directory: Choose the I/O options
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| − | IO::out_dir = $parfile
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| − | IO::out_fileinfo = "none"
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| − | IO::parfile_write = "no"
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| − | to ensure that the output directory has the right name, and that no
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| − | additional information is written into the output files.
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| − | Output quantities: Certain reduction operations (such as "sum") should
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| − | be avoided, since they change too much due to floating-point
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| − | round-off. The following reductions (and similar ones) are good;
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| − | others should be avoided:
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| − | * count minimum maximum average norm1 norm2 norm_inf
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| − | Do not use
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| − | * product sum sum_abs sum_squared sum_abs_squared
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| − | Screen output (info output) is ignored in test cases. You should
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| − | leave a bit of info output enabled, since this helps debugging, but it
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| − | won't be checked when the test case is run.
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| − | | |
| − | You will also want to beautify the parameter file at this point,
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| − | adding comments, and maybe adding your own name for vanity at the top.
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| − | You should also explain what the test case is testing.
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| − | Then you run the parameter file on two processes. After a short while
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| − | (under two minutes!), you should see an output directory. Have a look
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| − | into the output directory and check:
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| − | * Is there a ".par" file? (There should not.)
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| − | * Are there binary files? (There should not.)
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| − | * Are there large files? (There should not.)
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| − | * Are there many files? (There should not.)
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| − | | |
| − | Then move the parameter file as well as this output directory into the
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| − | "test" directory of the thorn you are testing.
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| − | | |
| − | Next, run this test case, following the Cactus instructions for doing
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| − | so. The test case should pass.
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| − | Don't forget to commit the test case, or to attach it to a patch you
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| − | are proposing.
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| − | | |
| − | ==How to track down why a test case fails==
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| − | | |
| − | (INCOMPLETE)
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| − | * Check out old code versions, find version that succeeds
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| − | * Output additional quantities, since the test case probably doesn't output enough data for this
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| − | * When doing so, keep several versions of the code/executable around, since you will be re-running the test cases many times
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