ran_unif Mersenne twister test: Resolution to Issue #499

[c-merchant]

Description:

Created ran_twist function that preserves the integer from ran_unif Mersenne twister PRNG.
Created test_ran_unif that runs ran_twist with a known seed, compare the integers produced against a reference solution for the Mersenne Twister.

Fixes issue

fixes #499

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update

Documentation changes needed?

• My change requires a change to the documentation.
  • I have updated the documentation accordingly.

Tests

Please describe any tests you ran to verify your changes.
I ran ./quickbuild.sh and ./runall.sh in ~/DART/developer_tests/random_seq/work

Checklist for merging

• Updated changelog entry
• Documentation updated
• Update conf.py

Checklist for release

• Merge into main
• Create release from the main branch with appropriate tag
• Delete feature-branch

Testing Datasets

• Dataset needed for testing available upon request
• Dataset download instructions included
• No dataset needed

[hkershaw-brown]

Hi Charlotte,

The public ran_twist routine to return the integer value has the correct code. The comments need updating to match what the routine returns (integer).

The new program test_ran_unif is not being compiled. You can check this with

./quickbuild.sh test_rand_unif
...
ERROR: unknown program test_rand_unif

the CCE 15 compiler on Derecho should fail your test ./test_rand_unif

The test_ran_unif is calling the new routine, and pass/failing. It has a bunch of legacy code from test_random which we don't really want to commit. I'll add some notes on what you can pull out shortly.

Cheers,
Helen

[hkershaw-brown]

@c-merchant looks good Charlotte!
Produces a fail for CCE 15 on Derecho, pass for other compilers.
There's some setup with ntests, and "save values for plotting" that we don't need for this test (the test passes or it fails). I'm going to go ahead and strip those out and we can bundle this with the next release.

Cheers,
Helen

[hkershaw-brown]

Approved!

[hkershaw-brown]

@hkershaw-brown you missed these two commits off this pull request
main...499