Package org.jgrapht.alg.flow.mincost
Interface MinimumCostFlowProblem<V,E>
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- Type Parameters:
V
- the graph vertex typeE
- the graph edge type
- All Known Implementing Classes:
MinimumCostFlowProblem.MinimumCostFlowProblemImpl
public interface MinimumCostFlowProblem<V,E>
This class represents a minimum cost flow problem. It serves as input for the minimum cost flow algorithms.The minimum cost flow problem is defined as follows: \[ \begin{align} \mbox{minimize}~& \sum_{e\in \delta^+(s)}c_e\cdot f_e &\\ \mbox{s.t. }&\sum_{e\in \delta^-(i)} f_e - \sum_{e\in \delta^+(i)} f_e = b_e & \forall i\in V\\ &l_e\leq f_e \leq u_e & \forall e\in E \end{align} \] Here $\delta^+(i)$ and $\delta^-(i)$ denote the outgoing and incoming edges of vertex $i$ respectively. The parameters $c_{e}$ define a cost for each unit of flow on the arc $e$, $l_{e}$ define minimum arc flow and $u_{e}$ define maximum arc flow.
- Author:
- Timofey Chudakov
- See Also:
MinimumCostFlowAlgorithm
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Nested Class Summary
Nested Classes Modifier and Type Interface Description static class
MinimumCostFlowProblem.MinimumCostFlowProblemImpl<V,E>
Default implementation of a Minimum Cost Flow Problem
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Method Summary
All Methods Instance Methods Abstract Methods Modifier and Type Method Description Function<E,Integer>
getArcCapacityLowerBounds()
Returns a function which specifies the minimum capacity of an arc.Function<E,Integer>
getArcCapacityUpperBounds()
Returns a function which specifies the maximum capacity of an arc.Graph<V,E>
getGraph()
Returns the flow networkFunction<V,Integer>
getNodeSupply()
Returns a function which defines the supply and demand of each node in thet network.
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Method Detail
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getNodeSupply
Function<V,Integer> getNodeSupply()
Returns a function which defines the supply and demand of each node in thet network. Supplies can be positive, negative or 0. Nodes with positive negative supply are the demand nodes, nodes with zero supply are the transhipment nodes. Flow is always directed from nodes with postive supply to nodes with negative supply. Summed over all nodes, the total demand should equal 0.- Returns:
- supply function
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getArcCapacityLowerBounds
Function<E,Integer> getArcCapacityLowerBounds()
Returns a function which specifies the minimum capacity of an arc. The minimum capacity is the minimum amount of flow that has to go through an arc.- Returns:
- arc capacity lower bounding function
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