Originally posted by: zyf2998

Hi, guys!
I have a problem to express the following constraint:

x is a real variable, which is greater or equal to 0(x >=0), y is a binary variable,
the relationship between x and y is : if x = 0, y = 0, if x > 0, y = 1.
How to represent y?

Thanks!
#DecisionOptimization
#OPLusingCPLEXOptimizer

Originally posted by: Prateep

Hi,

Assume M as a big number.

y >= x/M
y <= x*M

where x is a non negative real variable and y is a binary variable

I hope this will help you.

Thanks
Prateep
#DecisionOptimization
#OPLusingCPLEXOptimizer

Hi,

you can also write

dvar float+ x;
dvar boolean y;
 
subject to
{
  y == 1-(x==0); 
}

Alex
#DecisionOptimization
#OPLusingCPLEXOptimizer