XPRS_bo_addrows
XPRS_bo_addrows |
Purpose
Adds new constraints to a branch of a user branching object.
Synopsis
int XPRS_CC XPRS_bo_addrows(XPRSbranchobject obranch, int ibranch, int nrows, int nelems, const char crtype[], const double drrhs[], const int mrbeg[], const int mcol[], const double dval[]);
Arguments
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obranch
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The user branching object to modify.
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ibranch
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The number of the branch to add the new constraints for. This branch must already have been created using
XPRS_bo_addbranches. Branches are indexed starting from zero.
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nrows
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Number of new constraints to add.
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nelems
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Number of non-zero coefficients in all new constraints.
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crtype
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Character array of length
nrows indicating the type of constraints to add:
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drrhs
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Double array of length
nrows containing the right hand side values.
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mrbeg
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Integer array of length
nrows containing the offsets of the
mcol and
dval arrays of the start of the non zero coefficients in the new constraints.
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mcol
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Integer array of length
nelems containing the column indices for the non zero coefficients.
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dval
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Double array of length
nelems containing the non zero coefficient values.
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Example
The following function will create a branching object that branches on constraints
x_1 + x_2 ≥ 1 or
x_1 + x_2 ≤ 0:
XPRSbranchobject CreateConstraintBranch(XPRSprob xp_mip, int icol)
{
char cRowType;
double dRowRHS;
int mRowBeg;
int mElemCol[2];
double dElemVal[2];
XPRSbranchobject bo = NULL;
int isoriginal = 1;
/* Create the new object with two empty branches. */
XPRS_bo_create(&bo, xp_mip, isoriginal);
XPRS_bo_addbranches(bo, 2);
/* Add the constraint x1 + x2 >= 1. */
cRowType = 'G';
dRowRHS = 1.0;
mRowBeg = 0;
mElemCol[0] = 0; mElemCol[1] = 1;
dElemVal[0] = 1.0; dElemVal[1] = 1.0;
XPRS_bo_addrows
(bo, 0, 1, 2, &cRowType, &dRowRHS, &mRowBeg, mElemCol, dElemVal);
/* Add the constraint x1 + x2 <= 0. */
cRowType = 'L';
dRowRHS = 0.0;
XPRS_bo_addrows
(bo, 1, 1, 2, &cRowType, &dRowRHS, &mRowBeg, mElemCol, dElemVal);
/* Set a low priority value so our branch object is picked up */
/* before the default branch candidates. */
XPRS_bo_setpriority(bo, 100);
return bo;
}
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