Originally posted by: dapao12345

Hi

I have an IloNumArray D, an IloBoolVarArray B, and an IloNumExprArray E (where E[i] = D[i] * B[i] ).

I need find a way to express the non-zero mininum of E, and put it in a constrain.

However, since there are zeros in E, the 'IloMin()' function always takes zero as the minimum, which makes my problem insolvable .

I am wondering how to get the non-zero mininum from E.

Please help me out,  I am stuck here...
 

Thank you very much!!

Originally posted by: dapao12345

Can any body help me please, thanks.

If at least one of the variables in B is guaranteed to be non-zero then you could use

  min(D[0]*B[0], K * (1-B[0]), ..., D[n]*B[n], K * (1-B[n]))

where K is some large constant. This way B[i]=0 will contribute K to the minimum instead of 0.