Use min_ to get element wise minimum of a MVar and 1

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Weihang Zhang

2023年02月21日 22:33

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I have the following code and trying to get the elementwise minimum working, however I am getting an error "gurobipy.GurobiError: Invalid data in vars array". Can anyone tell me where I might be doing wrong? 

selection = model.addMVar((1, n1), vtype=gp.GRB.BINARY)

 

product = selection @ condition # condition is a sparse matrix of shape n1xn2

binary = model.addMVar((1, n2), vtype=gp.GRB.BINARY)

for i in range(n):

    model.addConstr(binary[0, i] == gp.min_(product[0, i], 1))

 

関連

• Matrix API

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• 正式なコメント

  

  Simranjit Kaur

  • Gurobi Staff

  2026年11月13日 01:48

  This post is more than two years old. Some information may not be up to date. For current information, please check the Gurobi Documentation or Knowledge Base. If you need more help, please create a new post in the community forum, or try Gurobot, our chatbot interface offering instant, expert-level support.
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  Riley Clement

  • Gurobi Staff

  2023年02月22日 00:55 編集済み

  Hi Weihang,

  The elements in your "product array" are gurobipy.MLinExpr.  The initial arguments to gurobipy.min_ need to be variables.  You can fix this by introducing auxiliary variables like so:

  # could be INTEGER if numbers in "condition matrix" are integer
  product_aux = m.addMVar(n2, vtype=gp.GRB.CONTINUOUS)
  
  for i in range(n2):
      m.addConstr(product_aux[i] == product[0, i])
      m.addConstr(binary[0, i] == gp.min_(product_aux[i] , 1))

  - Riley

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  Weihang Zhang

  2023年02月22日 09:51

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  Hi Riley,

  Thanks very much for the answer. It is clear now why it was not working previously. Really appreciate the help!

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