Christian Perau

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Activity overview

Latest activity by Christian Perau

  • Christian Perau commented,

    1. Community
    2. Programming
    3. Out of memory though memory is not exceeded

    After a while I found the source. I call the C-code from within python (via ctypes dll). In the corresponding anaconda environment I had gurobipy 11.0.1 installed. After installing gurobipy 11.0.3 ...

  • Christian Perau commented,

    1. Community
    2. Programming
    3. Out of memory though memory is not exceeded

    Hi Riley, I don´t set the Username in the code. However, the license file seems ok and it does work the first 253 iterations. I removed all gurobi versions from my machine and installed 11.0.3 agai...

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    • Christian Perau
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  • Christian Perau commented,

    1. Community
    2. Programming
    3. Out of memory though memory is not exceeded

    Hi Riley, yes I am using first GRBfreemodel and right after GRBfreeenv to free the memory. But I also monitored it in during runtime and the total memory usage of the machine was at its peak less t...

  • Christian Perau created a post,

    Out of memory though memory is not exceeded

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    1. Community
    2. Programming

    I am trying to solve a MILP using Bender's decomposition. Since there are many binary decision variables in the master, I need a lot of iterations. In the first iterations everything works just fin...

    • Christian Perau
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    • 7 comments
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  • Christian Perau created a post,

    Modelling squared euclidean distance in objective function (C-API)

    Answered
    1. Community
    2. Programming

    I want to implement the following objective function in the C-API: min (x²-1) + (y²-1) As far as I see it in the documentation I would need to reformulate the objective function to min x²-2x+1 + y²...

    • Christian Perau
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  • Christian Perau commented,

    1. Community
    2. Programming
    3. ValueError using model.addMConstr since gurobipy 11.0.0

    Hi Marika, thanks for the quick response! I know this problem actually existed before version 10 of gurobi. I also created a post regarding that a while ago (https://support.gurobi.com/hc/en-us/com...

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  • Christian Perau created a post,

    ValueError using model.addMConstr since gurobipy 11.0.0

    Answered
    1. Community
    2. Programming

    Since updating to gurobipy I receive an ValueError when I try to use addMConstr if I include constraint names. Here is a minimal reproducible example: import gurobipy as gpfrom gurobipy import GRBi...

    • Christian Perau
    • 4 followers
    • 3 comments
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  • Christian Perau commented,

    1. Community
    2. Systems
    3. using cmake -H. -Bbuild fails

    Adding option(BUILD_SHARED_LIBS "Build shared libraries" ON) to CMakeLists.txt was missing to write a .dll, by the way. But unfortunately if I load the corresponding .dll with ctypes.cdll.LoadLibra...

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    • Christian Perau
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    • 1 vote

  • Christian Perau commented,

    1. Community
    2. Systems
    3. using cmake -H. -Bbuild fails

    Hi Matthias, Thanks for the hint. Apparently instead of writing either a .dll or .so, the cmake build now creates a .lib file. I guess there will be some option on how to choose the file format, I´...

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  • Christian Perau commented,

    1. Community
    2. Systems
    3. using cmake -H. -Bbuild fails

    Hi Matthias, thanks for the explanation! I was wondering if it was possible to create a shared object (.so) file instead of the .exe file (or additionally to it) so that the function is callable vi...