Sajjad Hedayati

Gurobi-versary
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  • Total activity 14
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Activity overview

Latest activity by Sajjad Hedayati

  • Sajjad Hedayati commented,

    1. Community
    2. Programming
    3. Calling Shadow Prices Under Degeneracy

    Hi, Thank you for your suggestion. Although your solution seems to work, I couldn't have applied it to my model. I wonder if there is any solution to get those extreme points in which there are som...

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  • Sajjad Hedayati created a post,

    Calling Shadow Prices Under Degeneracy

    Ongoing
    1. Community
    2. Programming

    Dear Gurobi community I wonder if there is any possibility that we can get degeneracy information of a degenerate optimal basic feasible solution. In fact, I need to drop those constraints that are...

    • Sajjad Hedayati
    • 2 followers
    • 2 comments
    • 0 votes

  • Sajjad Hedayati commented,

    1. Community
    2. Algorithms
    3. Issues with adding valid inequalities

    I think that I have received the answer. Thank you, Mario!  

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  • Sajjad Hedayati created a post,

    Issues with adding valid inequalities

    Answered
    1. Community
    2. Algorithms

    Hi everyone I have a full integer model with both binary and positive integer variables. I would like to extract the relaxed LP solutions and apply some valid inequality. I already know that MIPNOD...

    • Sajjad Hedayati
    • 2 followers
    • 2 comments
    • 0 votes

  • Sajjad Hedayati commented,

    1. Community
    2. Algorithms
    3. Applying LR to the B&B for MIPs

    Thanks, Mario!

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  • Sajjad Hedayati commented,

    1. Community
    2. Algorithms
    3. Applying LR to the B&B for MIPs

    I think that I got my answer regarding the B&B. Thank you! What if we have a heuristic and we want to use its solution for our next optimization step by Gurobi? Like two-stage programming strategie...

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  • Sajjad Hedayati commented,

    1. Community
    2. Algorithms
    3. Applying LR to the B&B for MIPs

    Thank you again for your explanation. Now, I wonder if you could help me with the following strategy: - Imagine we get a lower bound and an infeasible solution that is integral obtained from an ind...

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  • Sajjad Hedayati commented,

    1. Community
    2. Algorithms
    3. Applying LR to the B&B for MIPs

    Hi Mario, Thank you for the information. According to your answer, two questions are possible: 1- If I implement my own branch-and-bound algorithm via gurobipy, I will need to use the LP model and ...

  • Sajjad Hedayati created a post,

    Applying LR to the B&B for MIPs

    Answered
    1. Community
    2. Algorithms

    Hi everyone I am trying to apply Lagrangian Relaxation to Branch-and-Bound to solve a MIP problem. How can I use LR during branching? I know that I have to use callbacks but I do not know how I can...

    • Sajjad Hedayati
    • 4 followers
    • 8 comments
    • 0 votes