mip solver: no endogenous operands for * allowed, but should be possible by division

GAMS
1

Hello everybody.

I need to do the following equation:
eq1(i,j) … losses =e= sum((i,j), loss_factor * net(i,j) * bin_trans(i,j) / 2);

According to my boss this must be done with mip solver.
But everytime I compile this it states that no endogenous operands for * are allowed.
I guess that means gams does not like the multiplication so it gets non linear.

Accoding to my boss this can be solved by a division. I don’t understand why a division should be any different.
He said the formula can be transformed into multiplication and divisions but how and why?

Could you tell me what he meant?

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2

Τη Τρίτη, 2 Ιουλίου 2013 9:41:44 π.μ. UTC+3, ο χρήστης rasa...@gmail.com έγραψε:

Hello everybody.

I need to do the following equation:
eq1(i,j) … losses =e= sum((i,j), loss_factor * net(i,j) * bin_trans(i,j) / 2);

According to my boss this must be done with mip solver.
But everytime I compile this it states that no endogenous operands for * are allowed.
I guess that means gams does not like the multiplication so it gets non linear.

Accoding to my boss this can be solved by a division. I don’t understand why a division should be any different.
He said the formula can be transformed into multiplication and divisions but how and why?

Could you tell me what he meant?


Hello,

from what i can think i do not believe tha this is a non linear problem because the equation is linear except for if you gave others non linear constraints. Do you try to use an lp solver? I have one more question. You do not use binary variable so why do you think that this is a milp problem? Finally, production and division are complementary mathematical operations so i do not believe that what your boss says is correct.

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