Adding Constraints

Answered

Swapnil Brahmankar

May 12, 2020 04:52

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Trying to add the following constraint, but keep getting TypeError: addConstrs() takes at least 2 positional arguments (1 given) error.

x = Decision variable, Binary variable, tupledict(loan, specname)

highballoanamt  = continuous variable, tupledict(loan, specname) : LoanAmt for High Balance loans

loanamt  = continuous variable, tupledict(loan, specname) : LoanAmt for all loans

What I am trying to achive is: For all the loans that got selected through optimizer, sum(HighBalLoanAmt) <= 0.20 * sum(LoanAmt)

hcfg = m.addConstrs(lhs = (x.prod(highballoanamt,'*', s) for s in specname
if (str.isnumeric(s) == False
and s.find('FG') != -1
and s.find('30') != -1)),
sense = GRB.LESS_EQUAL,
rhs = (0.20* x.prod(loanamt,'*', s) for s in specname
if (str.isnumeric(s) == False
and s.find('FG') != -1
and s.find('30') != -1)))

appreciate the help!

-1

• Official comment

  

  Simranjit Kaur

  • Gurobi Staff

  June 23, 2025 03:13 Edited

  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?.
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  Matthias Miltenberger

  • Gurobi Staff

  May 12, 2020 08:59

  Hi Swapnil,

  I would recommend finding the relevant elements in the specname list first. This should make constructing the constraint more readable.

  Furthermore, addConstrs(generator, name) does not accept lhs, rhs, and sense parameters. These are used for the addConstr() method.

  I hope that helps.

  Cheers,
  Matthias

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  Swapnil Brahmankar

  May 13, 2020 05:55

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  Thank you Matthias! let me try that, if you don't mind can you please point me to an example that has that construct? Thanks

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  Matthias Miltenberger

  • Gurobi Staff

  May 13, 2020 09:34

  You should check out the different examples - either in the examples directory or online. The diet one uses addConstrs(). I would recommend reading some of those to get a feeling of how to use the code.

  Cheers,
  Matthias

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