Hello, I am using Gurobi in Julia to solve a large MIP. When I run my program, Gurobi starts printing out some information shown in the two images attached to this question. I would very much like to understand each thing it is doing. I have taken courses in linear and integer programming, but I am still confused about several of the things it is outputting. Clarification on even just some of the things would be much appreciated if there are too many questions.
It first does the stuff in the first image shown here:
My questions regarding this first image are circled in red. Namely, could someone please tell me what the following mean (listed in order of the circles):
- Presolving (I am guessing this means just getting rid of redundant constraints?)
- Root barrier logs
- Ordering time
- Barrier statistics
- Root simplex log
- Primal Inf
- Dual Inf
Later on, the program then Gurobi then prints out the following:
Again, the stuff I am confused about are circled in red. Namely, could someone please tell me what the following mean:
- Concurrent spin time
- Solved with dual simplex (I guess this just means it solved the linear relaxation with the dual simplex method? If someone can confirm this that would be great though)
- Work units
- All the things in the header of the table it prints out
- What the H's mean on the side of the table
I realize there are many questions included in this post, but if someone could answer them or even just some of them that would be very much appreciated! Thank you!
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