# HG changeset patch
# User Robert L. Miller <rlm@rlmiller.org>
# Date 1261086646 28800
# Node ID 7d3cec74319d395e7ab08000f5e5e47e81a45d6c
# Parent 3b53b34d5093c4213f06a8bedd80658cdce0414e
Fix some optional docests in feedback functions
diff -r 3b53b34d5093 -r 7d3cec74319d sage/graphs/graph.py
a
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b
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12852 | 12852 | |
12853 | 12853 | sage: g = graphs.RandomGNP(5,.3) |
12854 | 12854 | sage: dg = DiGraph(g) |
12855 | | sage: feedback = dg.feedback_edge_set() |
| 12855 | sage: feedback = dg.feedback_edge_set() # optional - requires GLPK or CBC |
12856 | 12856 | sage: (u,v,l) = g.edge_iterator().next() |
12857 | | sage: (u,v) in feedback or (v,u) in feedback |
| 12857 | sage: (u,v) in feedback or (v,u) in feedback # optional - requires GLPK or CBC |
12858 | 12858 | True |
12859 | 12859 | """ |
12860 | 12860 | |
… |
… |
|
12952 | 12952 | sage: dcycle=DiGraph(cycle) |
12953 | 12953 | sage: cycle.vertex_cover(value_only=True) # optional - requires GLPK or CBC |
12954 | 12954 | 3 |
12955 | | sage: feedback = dcycle.feedback_vertex_set() # optional - requires GLPK or CBC |
12956 | | sage: feedback.cardinality() |
| 12955 | sage: feedback = dcycle.feedback_vertex_set() # optional - requires GLPK or CBC |
| 12956 | sage: feedback.cardinality() # optional - requires GLPK or CBC |
12957 | 12957 | 3 |
12958 | 12958 | sage: (u,v,l) = cycle.edge_iterator().next() |
12959 | | sage: u in feedback or v in feedback |
| 12959 | sage: u in feedback or v in feedback # optional - requires GLPK or CBC |
| 12960 | True |
12960 | 12961 | |
12961 | 12962 | For a circuit, the minimum feedback arc set is clearly `1` :: |
12962 | 12963 | |
12963 | 12964 | sage: circuit = digraphs.Circuit(5) |
12964 | | sage: circuit.feedback_vertex_set(value_only=True) == 1 |
| 12965 | sage: circuit.feedback_vertex_set(value_only=True) == 1 # optional - requires GLPK or CBC |
12965 | 12966 | True |
12966 | 12967 | """ |
12967 | 12968 | |