Jiangfei DUAN

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Activity overview

Latest activity by Jiangfei DUAN

  • Jiangfei DUAN commented,

    1. Community
    2. Other
    3. gurobi set initial solution slow down the solver

    Hi, Thanks for your reply. I set a partial solution, but it solves the partial solution quickly, and here is my log. The log without setting initial solution Academic license - for non-commercial ...

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    • Jiangfei DUAN
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  • Jiangfei DUAN commented,

    1. Community
    2. Programming
    3. Gurobi MILP branch-and-cut algorithm

    Hi, Jaromił, Thanks a lot. You can work with gurobipy and its objects the same way as with other Python modules. This means that you can use other modules such as, e.g., numpy, and the algorithm i...

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  • Jiangfei DUAN created a post,

    gurobi set initial solution slow down the solver

    Ongoing
    1. Community
    2. Other

    Hi, gurobi community, I am trying to use an initial solution to speed up the solver (MILP model). But in my case, the initial solution sometimes slow down the solving speed.  Here are my two result...

    • Jiangfei DUAN
    • 2 followers
    • 3 comments
    • 0 votes

  • Jiangfei DUAN commented,

    1. Community
    2. Programming
    3. Gurobi MILP branch-and-cut algorithm

    Hi, Sorry for my late reply. With the algorithm, I only need to keep K+2 nodes at most at the same time, which can reduce most of the nodes. I think, this can reduce memory (I am not sure if my und...

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  • Jiangfei DUAN created a post,

    Gurobi MILP branch-and-cut algorithm

    Answered
    1. Community
    2. Programming

    Hi, gurobi community, I am trying yo solve a MILP problem with gurobipy.  But my model is too large with millions vars and constraints.  When solving the problem, I notified that the memory is runn...

    • Jiangfei DUAN
    • Edited
    • 2 followers
    • 5 comments
    • 0 votes

  • Jiangfei DUAN commented,

    1. Community
    2. Algorithms
    3. How to determine the speed bottleneck of my Model?

    Hi, Matthias, Thanks a lot, I am trying to follow your advices. But I find, maybe the best way to speed up is to reformulate my model with linear constraints only... Besides, I have a question. I t...

  • Jiangfei DUAN created a post,

    How to determine the speed bottleneck of my Model?

    Answered
    1. Community
    2. Algorithms

    Hi, I am new to Linear Programming. To solve my problem, I modeling a complex model, and it takes too long to get a result. I want to speed up it, but I cannot point out the bottleneck. 1. I wonder...

    • Jiangfei DUAN
    • Edited
    • 2 followers
    • 3 comments
    • 0 votes

  • Jiangfei DUAN commented,

    1. Community
    2. Modeling
    3. How to model the problem of cutting a polyhedron into parts

    Thanks a lot. I got it. 

  • Jiangfei DUAN created a post,

    How to model the problem of cutting a polyhedron into parts

    Answered
    1. Community
    2. Modeling

    Hi, I met a problem in my modeling. Here I abstract a minimal question of my problem. Suppose I have a polyhedron (Rectangle, cube for example). For simplify, I use a rectangle as an example. The h...

    • Jiangfei DUAN
    • Edited
    • 2 followers
    • 2 comments
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  • Jiangfei DUAN commented,

    1. Community
    2. Programming
    3. var is a bound to be used in constraints

    Hi Matthias, Thanks for your reply. 1. \(d_i\) represents the dimension bound of the i-th dim, for example, a 3-dim array (2, 3, 4), \(d_0 = 2, d_1 = 3, d_2 = 4\), the array has 2*3*4 elements. ...