remove gRandom->SetSeed(0) from the compiled code

This MR removes all the resets of the random seed in the compiled code. I think we should keep the ability to reproduce all the results when a non-zero random seed is set by the main macro.

We need this option because of two reasons:

1. debugging - to reproduce problems, we need the ability to reproduce the data.

2. QA. We need the ability to compare different code versions on the same data. Since we run our test suite on a few events only, these events should be exactly the same. Otherwise, the performance fluctuates too much because of the low statistics and we are not able to catch unexpected changes in the results.

So, I think, gRandom->SetSeed(0) statement in the code is a bug.

TRandom3 myGenerator; is ok, because myGenerator's seed is always the same (==1234 or so).

myGenerator.SetSeed(0) is again a bug.

@f.uhlig, @v.friese, code owners,

Please let me know if you have any objections. I made this Merge Request instead of opening a redmine discussion because this way you can immediately see what files are affected.

added BugFix label

added 8 commits

• 8488688c...aff595e4 - 7 commits from branch computing:master
• e6de5c39 - remove resets of the random seed from the compiled code. We should keep the...

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Dear @praisig, @ebechtel_AT_ikf.uni-frankfurt.de, @c.muentz, @m.deveaux, @f.uhlig, @v.friese, @p.-a.loizeau,

you have been identified as code owner of at least one file which was changed with this merge request.

Please check the changes and approve them or request changes.

added CodeOwners label

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• 4b0a7aed - 1 commit from branch computing:master
• 463daba4 - remove resets of the random seed from the compiled code. We should keep the...

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From my side the update is fine, but may be we should announce the change several times, to make the analysis users aware of the change. On the PaPa usage I think this can have some unwanted influence if not handled in the steering macros correctly. I am adding @a_meye37_AT_uni-muenster.de, since he is currently the main user of PaPa.

approved this merge request

Ok, I have announced it through Redmine news. I intend to merge next Monday.

Since we did this cleanup meanwhile several times, should we also add a test to avoid reappearance of

gRandom->SetSeed()
new TRandom

Why not, if that can be done? gRandom->SetSeeed() should not be called, if I understand correctly.

But is it necessary to forbid the use of private random generators? A Sergey pointed out, only SetSeed(0) is evil w.r.t. reproducability.

added 22 commits

• 463daba4...43f19846 - 21 commits from branch computing:master
• 83ea1841 - remove resets of the random seed from the compiled code. We should keep the...

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added 1 commit

• 3e9701f0 - Removed German Umlaut from license header.

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added 3 commits

• 3ed463b8 - 1 commit from branch computing:master
• a78a6618 - remove resets of the random seed from the compiled code. We should keep the...
• b0ef2303 - Removed German Umlaut from license header.

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added 3 commits

• 83ea1841 - remove resets of the random seed from the compiled code. We should keep the...
• 3e9701f0 - Removed German Umlaut from license header.
• db031b02 - Introduce license disclaimer in requested format

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added 4 commits

• 3ed463b8 - 1 commit from branch computing:master
• 7023ef70 - remove resets of the random seed from the compiled code. We should keep the...
• dde07202 - Removed German Umlaut from license header.
• 1326cc4d - Introduce license disclaimer in requested format

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marked this merge request as ready

merged