branchobj.addrows
branchobj.addrows |
Purpose
Adds new constraints to a branch of a user branching object.
Synopsis
branchobj.addrows (ibranch, rtype, rhs, beg, mcol, val)
Arguments
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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
branchobj.addbranches. Branches are indexed starting from zero.
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rtype
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Character array of length
nrows indicating the type of constraints to add:
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rhs
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Array of length
nrows containing the right hand side values.
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beg
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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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Array of length
nelems containing the column indices for the non zero coefficients.
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dval
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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
x1 + x2 ≥ 1 or
x1 + x2 ≤ 0:
def CreateConstraintBranch (mip, icol):
# Create the new object with two empty branches.
bo = xpress.branchobj (mip, isoriginal = True)
bo.addbranches (2)
# Add the constraint of the branching object:
# x1 + x2 >= 1
# x1 + x2 <= 0
bo.addrows (0, 1, 2, ['G'], [1.0], [0], [0,1], [1.0,1.0])
bo.addrows (1, 1, 2, ['L'], [0.0], [0], [0,1], [1.0,1.0])
# Set a low priority value so our branch object is picked up
# before the default branch candidates.
bo.setpriority (100)
return bo