Package com.google.ortools.linearsolver

Class MPConstraint

  • public class MPConstraint
extends java.lang.Object
    The class for constraints of a Mathematical Programming (MP) model.

    A constraint is represented as a linear equation or inequality.

    • Field Summary

      Fields 
      Modifier and Type Field Description
      protected boolean swigCMemOwn  

    • Constructor Summary

      Constructors 
      Modifier Constructor Description
      protected MPConstraint​(long cPtr, boolean cMemoryOwn)  

    • Method Summary

      All Methods Static Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      MPSolver.BasisStatus basisStatus()
      Advanced usage: returns the basis status of the constraint.

      It is only available for continuous problems).

      Note that if a constraint "linear_expression in [lb, ub]" is transformed
      into "linear_expression + slack = 0" with slack in [-ub, -lb], then this
      status is the same as the status of the slack variable with AT_UPPER_BOUND
      and AT_LOWER_BOUND swapped.
      void delete()  
      double dualValue()
      Advanced usage: returns the dual value of the constraint in the current
      solution (only available for continuous problems).
      protected void finalize()  
      double getCoefficient​(MPVariable var)
      Gets the coefficient of a given variable on the constraint (which is 0 if
      the variable does not appear in the constraint).
      protected static long getCPtr​(MPConstraint obj)  
      int index()
      Returns the index of the constraint in the MPSolver::constraints_.
      boolean isLazy()
      Advanced usage: returns true if the constraint is "lazy" (see below).
      double lb()
      Returns the lower bound.
      java.lang.String name()
      Returns the name of the constraint.
      void setBounds​(double lb, double ub)
      Sets both the lower and upper bounds.
      void setCoefficient​(MPVariable var, double coeff)
      Sets the coefficient of the variable on the constraint.

      If the variable does not belong to the solver, the function just returns,
      or crashes in non-opt mode.
      void setIsLazy​(boolean laziness)
      Advanced usage: sets the constraint "laziness".

      This is only supported for SCIP and has no effect on other
      solvers.

      When laziness is true, the constraint is only considered by the Linear
      Programming solver if its current solution violates the constraint.
      void setLb​(double lb)
      Sets the lower bound.
      void setUb​(double ub)
      Sets the upper bound.
      protected static long swigRelease​(MPConstraint obj)  
      double ub()
      Returns the upper bound.

      • Methods inherited from class java.lang.Object

        clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Field Detail

      • swigCMemOwn

        protected transient boolean swigCMemOwn

    • Constructor Detail

      • MPConstraint

        protected MPConstraint​(long cPtr,
                       boolean cMemoryOwn)

    • Method Detail

      • getCPtr

        protected static long getCPtr​(MPConstraint obj)

      • swigRelease

        protected static long swigRelease​(MPConstraint obj)

      • finalize

        protected void finalize()
        Overrides:
        finalize in class java.lang.Object

      • delete

        public void delete()

      • name

        public java.lang.String name()
        Returns the name of the constraint.

      • setCoefficient

        public void setCoefficient​(MPVariable var,
                           double coeff)
        Sets the coefficient of the variable on the constraint.

        If the variable does not belong to the solver, the function just returns,
        or crashes in non-opt mode.

      • getCoefficient

        public double getCoefficient​(MPVariable var)
        Gets the coefficient of a given variable on the constraint (which is 0 if
        the variable does not appear in the constraint).

      • lb

        public double lb()
        Returns the lower bound.

      • ub

        public double ub()
        Returns the upper bound.

      • setLb

        public void setLb​(double lb)
        Sets the lower bound.

      • setUb

        public void setUb​(double ub)
        Sets the upper bound.

      • setBounds

        public void setBounds​(double lb,
                      double ub)
        Sets both the lower and upper bounds.

      • isLazy

        public boolean isLazy()
        Advanced usage: returns true if the constraint is "lazy" (see below).

      • setIsLazy

        public void setIsLazy​(boolean laziness)
        Advanced usage: sets the constraint "laziness".

        This is only supported for SCIP and has no effect on other
        solvers.

        When laziness is true, the constraint is only considered by the Linear
        Programming solver if its current solution violates the constraint. In this
        case, the constraint is definitively added to the problem. This may be
        useful in some MIP problems, and may have a dramatic impact on performance.

        For more info see: http://tinyurl.com/lazy-constraints.

      • index

        public int index()
        Returns the index of the constraint in the MPSolver::constraints_.

      • dualValue

        public double dualValue()
        Advanced usage: returns the dual value of the constraint in the current
        solution (only available for continuous problems).

      • basisStatus

        public MPSolver.BasisStatus basisStatus()
        Advanced usage: returns the basis status of the constraint.

        It is only available for continuous problems).

        Note that if a constraint "linear_expression in [lb, ub]" is transformed
        into "linear_expression + slack = 0" with slack in [-ub, -lb], then this
        status is the same as the status of the slack variable with AT_UPPER_BOUND
        and AT_LOWER_BOUND swapped.