g = Graph[{1, 2, 3, 4}, {1 <-> 2, 2 <-> 3, 3 <-> 1, 3 <-> 4},
EdgeCapacity -> {0.4, 0.6, 0.9, 0.7},
VertexLabels -> "Name"]; SetProperty[g,
EdgeLabels ->
MapThread[Rule, {EdgeList[g], PropertyValue[g, EdgeCapacity]}]]
FindMinimumCostFlow[g, 1, 3]
FindMinimumCostFlow[g, 1, 3, "FlowGraph"]
FindMinimumCostFlow[g, 1, 3, "FlowMatrix"] // MatrixForm