Modelica.Math.Vectors.normalize contains smooth(0,noEvent(...))

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Reported by stefanv on 11 Aug 2015 19:10 UTC
To the best of my knowledge, smooth and noEvent have no meaning inside functions.

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Migrated-From: https://trac.modelica.org/Modelica/ticket/1759

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Modified by beutlich on 18 Aug 2015 12:25 UTC

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Comment by otter on 28 Sep 2015 07:16 UTC
Replying to [ticket:1759 stefanv]:

To the best of my knowledge, smooth and noEvent have no meaning inside functions.

Fixed in cf31373:
Added the following comment in the code (trunk):

 This function has the inline annotation. If the function is inlined:
     - "smooth(..)" defines how often the expression can be differentiated
       (if symbolic processing is performed). 
     - "noEvent(..)" prevents event handling of the if-clause,
       in order to guard against division by zero.

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Modified by otter on 28 Sep 2015 07:17 UTC

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Comment by stefanv on 28 Sep 2015 13:48 UTC
But this means that the semantics of a function are different depending on whether or not it is successfully inlined. That should not be the case, and a tool that inlines a function should automatically add smooth and noEvent where needed.

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Comment by sjoelund.se on 28 Sep 2015 20:46 UTC
Replying to [comment:4 stefanv]:

But this means that the semantics of a function are different depending on whether or not it is successfully inlined. That should not be the case, and a tool that inlines a function should automatically add smooth and noEvent where needed.

Functions generate events when GenerateEvents=true. But it is not set here.

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Comment by otter on 13 Dec 2015 06:54 UTC
Fixed in 207cb79 by
removed noEvent (had no effect since inlining a function adds automatically noEvent).

Replying to [comment:4 stefanv]:

But this means that the semantics of a function are different depending on whether or not it is successfully inlined. That should not be the case, and a tool that inlines a function should automatically add smooth and noEvent where needed.

A tool cannot automatically add "smooth" because in general it cannot figure out how "smooth" an if-expression is.

If the function is not inlined, "smooth(..)" has no effect. If it is inlined, it gives additional information to the Modelica tool. The tool may or may not use this information (smooth(..) is defined in this way).

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Changelog modified by otter on 13 Dec 2015 06:54 UTC
Math.Vectors.normalize: Removed unnecessary noEvent(..)