fixing xhatters #481
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fixing xhatters #481
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bknueven
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DLWoodruff
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Jan 23, 2025
| @@ -83,7 +83,8 @@ def _vb(msg): | |||
| return False | |||
| _vb(f" Feasible {snamedict}, obj: {obj}") | |||
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| update = self.update_if_improving(obj) | |||
| # the xhatter updates the cache in the opt object for us | |||
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Basically, you want to cache the solution before the xhatter restores the nonants.
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Follow up from #461.
The changes in #461 were needed to ensure the solution written was nonanticipative. However, as a side effect, it made the xhatters less effective. Because
XhatBase._try_onedid not restore the nonants, when the "next" scenario was called it would have the previous solution loaded, and not the PH iteration loaded. Therefore the incumbent finders were only producing at most one solution per PH iteration.This PR fixes the same bug as #461, but does so my moving the best solution found tracking code into
SPBase. Then the Xhatters can update and cache the solution immediately after it is found, and then finally restoring the nonants for the next try. This also makes it much less likely that solutions found will be accidentally dropped because of a user configuration error.