jeffreydeankelly2

HiGHS Supplying a *.lib File Instead of the libhighs.dll.a

12

Hi All; When downloading the HiGHS binaries, only a libhighs.dll.a file is provided in the LIB sub-directory. I am wondering if you can supply a *.lib file as well as...

Small Linear Data Reconciliation QP Problem Solution Incorrect

3

Below is a relatively small linear data reconciliation problem formulated mathematically as a QP problem and output as a HiGHS LP file. When solved in IPOPT and our home-grown equality-constrained...

HiGHS Falsely Declares a MILP as Integer-Infeasible

8

I have been going through our set of internal industrial discrete and linear optimization problems (MILP) and have noticed that for the problem found in the LP and MPS files...

HiGHS Falsely Declares a MILP as Provably Optimal

2

Attached are the LP and MPS files for a MILP problem which has a provably optimal objective function of > -14.0 but HiGHS declares it as provably optimal at -18.2....

"WARNING: Solution with objective XXX has untransformed violations: bound = ..." seems to accurately predict integer-infeasibility in the MIP.

5

I have been researching primal heuristics with HiGHS' MIP and I have noticed that when the following message occurs: WARNING: Solution with objective 95.5311 has untransformed violations: bound = 1.073...

Prevent the Highs instance from being called by a callback that it calls.

5

I recently upgraded to HiGHS 1.6.0 using JuMP supplied Windows non-static binaries and added the MIP logging and improving solution callbacks - thank you for adding these. I interfaced the...

User callback interrupt (HighsCallbackDataIn%user_interrupt, Fortran syntax) does not seem to work for release 1.7.0

6

Installed version 1.7.0. Everything works great for our set of MIP problems but when the user callback sets the HighsCallbackDataIn data structure item user_interrupt to some non-zero value after a...

HiGHS 1.7.1 HighsCallbackDataOut data type can no longer be accessed directly for mip_solution item.

1

I know that in 1.7.1 the item pdlp_iteration_count is moved to the end of the HighsCallbackDataOut data type but this now breaks the direct access of the mip_solution our Intel...

How to Set a Partial MIP Solution using setSolution()?

2

Is it possible to load a subset of "MIP starts" for a partial subset of the binary variables using setSolution() i.e., only setting the binary variables that are at one...

HIGHS 1.7.2. MIP solver terminates prematurely due to error in dual bound

14

[gaswellrig_lpfile.txt](https://github.com/user-attachments/files/16482713/gaswellrig_lpfile.txt) [gaswellrig_mpsfile.txt](https://github.com/user-attachments/files/16482715/gaswellrig_mpsfile.txt) Attached are the LP and MPS file for a MIP problem which terminates at a gap of 5.36% but the gap is set to your defaults i.e., mip_rel_gap...