# Edge isoperimetric number

This is probably a very silly question. How does one get the edge isoperimetric number of a graph?

As seen under here there should be an algorithm for it, but when I define a graph (say H), then

```
edge_isoperimetric_number(H)
```

returns "name 'edge_isoperimetric_number' is not defined"

and

```
H.edge_isoperimetric_number()
```

returns "'Graph' object has no attribute 'edge_isoperimetric_number'"

(while

```
edge_isoperimetric_number?
```

returns "Object `edge_isoperimetric_number`

not found."

So how do I load said algorithm for use?

This ticket has not been merged in sage, so that code is not available. You can try to use git to pull the branch on the ticket page, fix the merge conflict and recompile sage after.

Thanks...I've never done that before: what is the merge conflict (or how does one fix such a conflict)?

Actually how does one pull this branch? I don't know how to use the commit number 9a0062d887faa15d6e694f7143bd37514f31d790

So far... I :

git clone git://github.com/sagemath/sage.git

but when I tried to do either

git fetch trac u/vdelecroix/21942

or

git pull u/vdelecroix/21942

or

git checkout 7880791d25423e16db76c5f855998818c3c8c45e

or many other numbers in the checkout. But it always returns a error message.