# Maliheh Aramon

Gurobi Staff
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## Activity overview

Latest activity by Maliheh Aramon
• Maliheh Aramon commented,

Hi Shawn,  Please see the code snippet below using the Gurobi Matrix API in version 10.0 as an example implementation. It is assumed that $$X$$ is a binary matrix and a nonzero row refers to a row ...

• Maliheh Aramon commented,

Hi Zvonimir,  As mentioned in our documentation, the Model.addConstrs() method returns a tupledict where the constraints are indexed by the values of the generator expression. In your code, I guess...

• Maliheh Aramon commented,

Hi Noah,  Thank you for contacting us!  You have a commercial account with us. We converted your question into a ticket and we will get back to you through the ticket.  Best regards, Maliheh

• Maliheh Aramon commented,

Hi Anjula,  Yes, using these parameters typically comes at the cost of increasing the runtime, although there is no guarantee that the extra care given to numerics would result in a clean barrier s...

• Maliheh Aramon commented,

Hi Shahab,  As already mentioned, the difficulty of a model is not necessarily a function of its size. A similar idea still works if $$\texttt{LKN}$$ are integer variables. Let us refer to $$\textt... • Maliheh Aramon commented, Hi Anjula, Yes, this is a common issue for the QCP models with challenging numerics. Scaling your model manually, if possible, to ensure the model numerics look reasonable is the best approach to a... • Maliheh Aramon commented, Hi Shahab, The model that I use works, fortunately, but the size of the Matrix forces causes a long execution time of the Gourbi Using auxiliary variables to enforce constraints is not necessari... • Maliheh Aramon commented, Hi Wentao, You can use the method Model.getCol(var) to get a Column object capturing the constraints that the variable \(\texttt{var}$$ participates in. Hope this helps. Best regards, Maliheh

• Maliheh Aramon commented,

Hi Somreeta,  If $$\mbox{erf}(z)$$ is a linear function of $$z$$ decision variable, you can define an auxiliary binary variable $$x$$ where: $\mbox{if}~~ z \leq 0 \rightarrow x = 1$ \[\mbox{if}~~...

• Maliheh Aramon commented,

Hi,  This can happen if the variables $$e_{sum}^j$$ and $$t_{sum}^j$$ are defined to be always $$\geq 0$$. When adding a variable to the model, its lb is set to 0 by default. If these variables can...