
From:  Meketon, Marc 
Subject:  Re: [Helpglpk] "multiplication of linear forms not allowed" 
Date:  Sun, 21 Oct 2012 14:41:00 0500 
Xypron used "M" as a large constant (e.g., 9999). Not as a binary variable. param M := 9999; var B{J,K} >= 0; s.t. a{j in J}: M*sum{k in K}B[j,k] <= A[j] <= M*sum{k in K}B[j,k]; Original Message I'm trying to apply the following constraint following a suggestion by xypron: var M{J} ,binary; var B{J,K} ,>= 0; s.t. a{j}: M[j]*sum{k in K}B[j,k] <= A[j] <= M[j]*sum{k in K}B[j,k]; The goal being to force A[j] = 0 if the sum over k of B[j,k] = 0; glpsol 4.47 exits w/ the message in the subject line. I found Steglich's post of last month, but am having trouble w/ translating the notation in the CMPL 1.7.0 manual to GMPL. From context, I'm guessing that overbar indicates the maximum and underbar the minimum, but I can find nothing to confirm that. The first equation in section 8.3.1 appears to have a typo as there is no underbar in the range specification.
Even if I assume the typo, and explicitly specify the additional variables and constraints, I still get the subject line message. Just at a different point. Is it possible to do this in GMPL? If so, how? At the moment, the only option I can see would be to make an initial solution w/o the constraint and then recast the problem and solve again. Thanks, Reg _______________________________________________ Helpglpk mailing list This email and any attachments may be confidential or legally privileged. If you received this message in error or are not the intended recipient, you should destroy the email message and any attachments or copies, and you are prohibited from retaining, distributing, disclosing or using any information contained herein. Please inform us of the erroneous delivery by return email. Thank you for your cooperation. 
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