Multiplying linear expressions in Java

[Zhihao Chen]

I was wondering if there was a way to create a quadratic expression by multiplying two linear expressions. I know in C++ you can simply multiply them

i.e. GRBQuadExpr = GRBLinExpr*GRBLinExpr

but is there a similar way to do this in Java?

[Jakob Sch.]

Hi Zhihao,

my guess would be that you have to use

GRBQuadExpr.addTerms()

see http://www.gurobi.com/documentation/5.6/reference-manual/java_grbquadexpr_addterms

Best regards,
Jakob

[Zhihao Chen]

Thanks for your reply Jakob! GRBQuadExpr.addTerms() only works if you have two GRBVars though.. I have a more complicated expression and was hoping of multiplying two GRBLinExprs instead of multiplying the expression by hand then using GRBQuadExpr.addTerms().

Zhihao

[Greg Glockner]

Create new variables that equal the GRBLinExpr terms, then multiply them. The overhead will be handled in presolve.

[Zhihao Chen]

Thank you, that solved the problem!

Zhihao