Help with a conditional constraint!

回答済み

Abhishek Solomon

2022年07月14日 19:25

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Hello,

I have the following code block:

for i in locations:
            for o in facilityoptions:
                m.addConstr(gp.quicksum(ProductionQty[p,i,o]/yieldpersqft[p,o] for p in setproduce) <= sqft[o]*LocationSelect[i,o], 'SqftConstraint')

My issue is that yieldpersqft[p,o] is 0 in some cases, and hence i get a divide by zero error. I need this constraint to hold only when yieldpersqft[p,o] > 0.

I saw some help topics on this, and i tried the following:

for i in locations:
            for o in facilityoptions:
                m.addConstr((yieldpersqft[p,o]>0.1) >> (gp.quicksum(ProductionQty[p,i,o]/yieldpersqft[p,o] for p in setproduce) <= sqft[o]*LocationSelect[i,o], 'SqftConstraint'))

But this does not work due to p not being initialized prior. Any tips on how to proceed?

Thanks in advance!

 

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• 正式なコメント

  

  Simranjit Kaur

  • Gurobi Staff

  2025年11月16日 23:32

  This post is more than three 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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  Eli Towle

  • Gurobi Staff

  2022年07月14日 21:19

  Is \( \texttt{yieldpersqft} \) fixed data that is known beforehand? If so, you can add a conditional statement to your \( \texttt{for} \) loop so you only sum terms for which \( \texttt{yieldpersqft[p, o]} \) is strictly positive:

  for i in locations:
      for o in facilityoptions:
          m.addConstr(
              gp.quicksum(
                  ProductionQty[p, i, o] / yieldpersqft[p, o]
                  for p in setproduce
                  if yieldpersqft[p, o] > 0
              )
              <= sqft[o] * LocationSelect[i, o],
              "SqftConstraint",
          )

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  Abhishek Solomon

  2022年07月15日 03:57

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  Thank you Eli Towle ! Yes, yieldpersqft is fixed data. I will try this and come back if there's any other issue.

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