Bugfix: FBBT with ExternalFunction expressions #2657
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| if not node.is_potentially_variable(): | ||
| # NPV nodes are effectively constant leaves. Evaluate it | ||
| # and return the value. | ||
| val = value(node) | ||
| self.bnds_dict[node] = (val, val) | ||
| return True, None |
| if self.tightener is not fbbt: | ||
| raise unittest.SkipTest('Appsi FBBT does not support unkown expressions yet') |
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Should we add a ticket to remind ourselves to add ExternalFunctionExpression to APPSI? I believe the issue is not actually the ExternalFunctionExpression, but rather that they are allowed (by AMPL and Pyomo) to have str arguments.
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I'm fairly certain an exception would be raised somewhere else if we fixed the str problem. Yes, we should add a ticket.
Codecov ReportBase: 87.03% // Head: 87.06% // Increases project coverage by
Additional details and impacted files@@ Coverage Diff @@
## main #2657 +/- ##
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+ Coverage 87.03% 87.06% +0.03%
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Files 754 754
Lines 84051 84362 +311
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+ Hits 73151 73448 +297
- Misses 10900 10914 +14
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Fixes #2650 .
Summary/Motivation:
This resolves exceptions raised by FBBT for expressions containing
ExternalFunctionExpressionnodes with string arguments. This works by treating External Functions as unbounded leaf nodes in both the root-to-leaf and leaf-to-root walkers.Changes proposed in this PR:
ExternalFunctionExpressionnodesis_potentially_variableand treat them as constant nodes as opposed to descending into them)Legal Acknowledgement
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