
constraint handler for SOS type 2 constraints
 Author
 Marc Pfetsch
A specially ordered set of type 2 (SOS2) is a sequence of variables such that at most two variables are nonzero and if two variables are nonzero they must be adjacent in the specified sequence. Note that it is in principle allowed that a variable appears twice, but it then can be fixed to 0 if it is at least two apart in the sequence.
Definition in file cons_sos2.h.
Go to the source code of this file.

SCIP_RETCODE  SCIPincludeConshdlrSOS2 (SCIP *scip) 

SCIP_RETCODE  SCIPcreateConsSOS2 (SCIP *scip, SCIP_CONS **cons, const char *name, int nvars, SCIP_VAR **vars, SCIP_Real *weights, SCIP_Bool initial, SCIP_Bool separate, SCIP_Bool enforce, SCIP_Bool check, SCIP_Bool propagate, SCIP_Bool local, SCIP_Bool dynamic, SCIP_Bool removable, SCIP_Bool stickingatnode) 

SCIP_RETCODE  SCIPcreateConsBasicSOS2 (SCIP *scip, SCIP_CONS **cons, const char *name, int nvars, SCIP_VAR **vars, SCIP_Real *weights) 

SCIP_RETCODE  SCIPaddVarSOS2 (SCIP *scip, SCIP_CONS *cons, SCIP_VAR *var, SCIP_Real weight) 

SCIP_RETCODE  SCIPappendVarSOS2 (SCIP *scip, SCIP_CONS *cons, SCIP_VAR *var) 

int  SCIPgetNVarsSOS2 (SCIP *scip, SCIP_CONS *cons) 

SCIP_VAR **  SCIPgetVarsSOS2 (SCIP *scip, SCIP_CONS *cons) 

SCIP_Real *  SCIPgetWeightsSOS2 (SCIP *scip, SCIP_CONS *cons) 

creates the handler for SOS2 constraints and includes it in SCIP
 Parameters

SCIP_RETCODE SCIPcreateConsSOS2 
( 
SCIP * 
scip, 


SCIP_CONS ** 
cons, 


const char * 
name, 


int 
nvars, 


SCIP_VAR ** 
vars, 


SCIP_Real * 
weights, 


SCIP_Bool 
initial, 


SCIP_Bool 
separate, 


SCIP_Bool 
enforce, 


SCIP_Bool 
check, 


SCIP_Bool 
propagate, 


SCIP_Bool 
local, 


SCIP_Bool 
dynamic, 


SCIP_Bool 
removable, 


SCIP_Bool 
stickingatnode 

) 
 
creates and captures an SOS2 constraint
We set the constraint to not be modifable. If the weights are non NULL, the variables are ordered according to these weights (in ascending order).
 Note
 the constraint gets captured, hence at one point you have to release it using the method SCIPreleaseCons()
 Parameters

scip  SCIP data structure 
cons  pointer to hold the created constraint 
name  name of constraint 
nvars  number of variables in the constraint 
vars  array with variables of constraint entries 
weights  weights determining the variable order, or NULL if natural order should be used 
initial  should the LP relaxation of constraint be in the initial LP? Usually set to TRUE. Set to FALSE for 'lazy constraints'. 
separate  should the constraint be separated during LP processing? Usually set to TRUE. 
enforce  should the constraint be enforced during node processing? TRUE for model constraints, FALSE for additional, redundant constraints. 
check  should the constraint be checked for feasibility? TRUE for model constraints, FALSE for additional, redundant constraints. 
propagate  should the constraint be propagated during node processing? Usually set to TRUE. 
local  is constraint only valid locally? Usually set to FALSE. Has to be set to TRUE, e.g., for branching constraints. 
dynamic  is constraint subject to aging? Usually set to FALSE. Set to TRUE for own cuts which are separated as constraints. 
removable  should the relaxation be removed from the LP due to aging or cleanup? Usually set to FALSE. Set to TRUE for 'lazy constraints' and 'user cuts'. 
stickingatnode  should the constraint always be kept at the node where it was added, even if it may be moved to a more global node? Usually set to FALSE. Set to TRUE to for constraints that represent node data. 
creates and captures a SOS2 constraint with all constraint flags set to their default values.
 Warning
 Do NOT set the constraint to be modifiable manually, because this might lead to wrong results as the variable array will not be resorted
 Note
 the constraint gets captured, hence at one point you have to release it using the method SCIPreleaseCons()
 Parameters

scip  SCIP data structure 
cons  pointer to hold the created constraint 
name  name of constraint 
nvars  number of variables in the constraint 
vars  array with variables of constraint entries 
weights  weights determining the variable order, or NULL if natural order should be used 
adds variable to SOS2 constraint, the position is determined by the given weight
 Parameters

scip  SCIP data structure 
cons  constraint 
var  variable to add to the constraint 
weight  weight determining position of variable 
appends variable to SOS2 constraint
 Parameters

scip  SCIP data structure 
cons  constraint 
var  variable to add to the constraint 
gets number of variables in SOS2 constraint
 Parameters

scip  SCIP data structure 
cons  constraint 
gets array of variables in SOS2 constraint
 Parameters

scip  SCIP data structure 
cons  constraint data 
gets array of weights in SOS2 constraint (or NULL if not existent)
 Parameters

scip  SCIP data structure 
cons  constraint data 
