Initializing help system before first use

XPRBaddqterm

XPRBaddqterm


Purpose
Add a quadratic term to a constraint.
Synopsis
int XPRBaddqterm(XPRBctr ctr, XPRBvar var1, XPRBvar var2, double coeff);
Arguments
ctr 
Reference to a constraint.
var1 
Reference to a variable.
var2 
Reference to a variable (not necessarily different).
coeff 
Value to be added to the coefficient of the term var1 * var2.
Return value
0 if function executed successfully, 1 otherwise.
Example
The following example adds the term -2*x2*x4 to the constraint ctr1:
XPRBctr ctr1;
XPRBvar x2,x4;
 ...
ctr1 = XPRBnewctr(prob, "r1", XPRB_L);
x2 = XPRBnewvar(prob, XPRB_PL, "abc1", 0, XPRB_INFINITY);
x4 = XPRBnewvar(prob, XPRB_PL, "abc5",0 , XPRB_INFINITY);
XPRBaddqterm(ctr1, x2, x4, -2); 
Further information
This function adds a new quadratic term to a constraint, comprising the product of the variables var1 and var2 with coefficient coeff. If the constraint already has a term with variables var1 and var2, coeff is added to its coefficient.
Note:
all terms that are added to a constraint must belong to the same problem as the constraint itself.

Related topics