1 | initial version |

To create a graph from an adjacency matrix, use the following:

```
sage: M = matrix(ZZ,8,8,[0,1,1,1,0,0,0,0,
1,0,0,0,1,1,0,0,
1,0,0,0,0,1,1,0,
1,0,0,0,1,0,1,0,
0,1,0,1,0,0,0,0,
0,1,1,0,0,0,0,0,
0,0,1,1,0,0,0,1,
0,0,0,0,1,1,1,0])
sage: G = Graph(M,format='adjacency_matrix')
```

You can find more ways to create graphs by running "`Graph?`

" in Sage. To plot this graph you use the `Graph.plot()`

command.

```
sage: G.plot()
```

If the graph is a tree there's a special argument you can provide to `plot()`

that will make the formatting nicer.

```
sage: G.plot(layout='tree')
Traceback (click to the left of this block for traceback)
...
RuntimeError: Cannot use tree layout on this graph: self.is_tree()
returns False.
```

However, the graph you provided isn't really a tree. Run the first three commands above to see what I mean, just in case I entered your adjacency matrix incorrectly. Finally, if you do have a tree running

```
sage: G.plot?
```

will explain various other plotting options that might prove useful. In particular, options for specifying tree roots and such.

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