Originally posted by: SoumyaJ

Hi,
I have installed cplex124 linux version.
I want to solve equations which has multiplication both in constraints and in objective function.
But it is not supporting second order equations.
Is there any separate file format for multiplication to use in CPLEX?
I read that the version of cplex iam using supports quadratic equations.
But not sure how to use it.
Please help me
Thank you.
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Originally posted by: chintasunny

What kind of error are you seeing? CPLEX does not support all kinds of second order terms. It only supports convex functions.
Thanks
Sunil
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Originally posted by: SoumyaJ

Thanks for your quick reply...
The error is
Expected + or - but found *
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Originally posted by: chintasunny

This error clearly indicates that QP conventions are not followed properly. As Daniel suggested, you can go through the qp examples that comes with CPLEX. Alternatively you can also send the .lp file to this group.
Quick check:
The objective function in the lp file format should be in the following fashion:
Obj: a + b +a^2 + 4 a * b + 7 b^2/2
All the quadratic terms including asterisk (*) should be within square bracketrs. See if you are missing square brackets for quadratic function

Thanks
Sunil
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Originally posted by: SystemAdmin

You may want to take a look at one of the following examples that are shipped with CPLEX: qcpex1.c, xqcpex1.c, iloqcpex1.cpp, qcpex1.m, QCPex1.java, QCPex1.cs. They all illustrate how to create a problem with quadratic constraints in memory. They also write out the problem to a file so that you can learn the file format from that file.
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