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GRBaddgenconstrIndicator
| int | GRBaddgenconstrIndicator ( | GRBmodel | *model, |
| const char | *name, | ||
| int | binvar, | ||
| int | binval, | ||
| int | nvars, | ||
| const int | *ind, | ||
| const double | *val, | ||
| char | sense, | ||
| double | rhs ) |
Add a new general constraint of type GRB_GENCONSTR_INDICATOR to a model. Note that, due to our lazy update approach, the new constraint won't actually be added until you update the model (using GRBupdatemodel), optimize the model (using GRBoptimize), or write the model to disk (using GRBwrite).
An INDICATOR constraint
states that if the binary
indicator variable 
is equal to 
, where 
, then the linear constraint
should hold.
On the other hand, if 
, the linear constraint may be violated.
The sense of the linear constraint can also be specified to be “
” or “
”.
Note that the indicator variable of a constraint will be forced
to be binary, independent of how it was created.
Arguments:
model: The model to which the new general constraint should be added.
name: Name for the new general constraint. This argument can be NULL, in which case the constraint is given a default name.
binvar: The index of the binary indicator variable .
binval: The value for the binary indicator variable that would
force the linear constraint to be satisfied (
or 
).
nvars: The number 
of non-zero coefficients in the linear constraint
triggered by the indicator.
ind: Indices for the variables 
with non-zero values in
the linear constraint.
val: Numerical values for non-zero values 
in
the linear constraint.
sense: Sense for the linear constraint. Options are GRB_LESS_EQUAL, GRB_EQUAL, or GRB_GREATER_EQUAL.
rhs: Right-hand side value for the linear constraint.
Return value:
A non-zero return value indicates that a problem occurred while adding the general constraint. Refer to the Error Code table for a list of possible return values. Details on the error can be obtained by calling GRBgeterrormsg.
Example usage:
/* x7 = 1 -> x1 + 2 x3 + x4 = 1 */
int ind[] = {1, 3, 4};
double val[] = {1.0, 2.0, 1.0};
error = GRBaddgenconstrIndicator(model, NULL, 7, 1,
3, ind, val, GRB_EQUAL, 1.0);
