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https://issues.apache.org/jira/browse/MATH-1549?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17162286#comment-17162286
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Mohammad Rezaei commented on MATH-1549:
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I added the exponent routines to Precision (NUMBERS-148). I'm not sure how I
feel about the overall scaling though. It seems very specific to the linear
solver, and as I was researching this, I came across other scaling algorithms,
so I'm not sure it would be of general interest/use.
> Simplex solver report unbounded solution when solvable constraints scaling up
> -----------------------------------------------------------------------------
>
> Key: MATH-1549
> URL: https://issues.apache.org/jira/browse/MATH-1549
> Project: Commons Math
> Issue Type: Bug
> Affects Versions: 3.6.1
> Environment: macOS catalina
> Reporter: Fan Zhang
> Priority: Major
> Fix For: 4.0
>
> Attachments: CommonsMathSimplexSolverTest.java
>
> Time Spent: 1h 10m
> Remaining Estimate: 0h
>
> *scenario 1:*
> {code:java}
> min: x + y
> x, y >= 0
> 9000x + y >= 0
> 10000x + y >= 2000
> x >= 2{code}
> *scenario 2:*
> {code:java}
> min: x + y
> x, y >= 0
> 9.0E15x + 1.0E12y >= 0
> 1.1e16x + 1.0e12y >= 2.0e15
> 1.0e12x >= 2e12{code}
> for scenario 1, it works out. but for scenario 2 whose constrains are just
> scaled up by 1e12, the solver reports unbounded solution.
>
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