problem in modeling "keyerror = 0"

回答済み

Azmi Jundan Taqiy

2021年11月25日 04:45

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I got troubled with an error stating "KeyError = 0" on the model objective function

 

from gurobipy import *

# SET
RM = 7
RAW = range(RM) # index r
CE = 3
COMP = range(CE) # index c

# PARAMETER
PMIN_c = [2, 0.4, 1.2]
PMAX_c = [3, 0.6, 1.65]

P_rc = [[2.5, 0, 1.3],
[3, 0, 0.8],
[0, 0.3, 0],
[0, 90, 0],
[0, 96, 4],
[0, 0.4, 1.2],
[0, 0.6, 0]]

AVAIL_r = [400, 300, 600, 500, 200, 300, 250, 500]

COST_r = [200, 250, 150, 220, 240, 200, 165]

DEM = 500

# MODEL
m = Model()

# DECISION VARIABLE
use_r = m.addVars(RAW, COMP, vtype=GRB.CONTINUOUS, name="materials used")

# OBJECTIVE FUNCTION
m.setObjective(quicksum(COST_r[r] * use_r[r] for r in RAW), GRB.MINIMIZE)

0

• 正式なコメント

  

  Simranjit Kaur

  • Gurobi Staff

  2025年06月23日 02:44 編集済み

  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 why not try our AI Gurobot?.
• 

  Jaromił Najman

  • Gurobi Staff

  2021年11月26日 09:05

  Your variables are defined over 2 lists \(\texttt{RAW}\) and \(\texttt{COMP}\). Thus, you have to access variables \(\texttt{use_r}\) via

  m.setObjective(quicksum(COST_r[r] * use_r[r,c] for r in RAW for c in COMP), GRB.MINIMIZE)

  Best regards,
  Jaromił

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