For now, every algorithms class is composed with a static method called `compare()`. `compare()` takes
two arguments :
In `Gmatch4py`, algorithms manipulate `networkx.Graph`, a complete graph model that
comes with a large spectrum of parser to load your graph from various inputs : `*.graphml,*.gexf,..` (check [here](https://networkx.github.io/documentation/stable/reference/readwrite/index.html) to see all the format accepted)
### Use Gmatch4py
If you want to use algorithms like *graph edit distances*, here is an example:
```{python}
# Gmatch4py use networkx graph
import networkx as nx
# import the GED using the munkres algorithm
from gmatch4py.ged.graph_edit_dist import GraphEditDistance
```
In this example, we use generated graphs using `networkx` helpers:
```{python}
g1=nx.complete_bipartite_graph(5,4)
g2=nx.complete_bipartite_graph(6,4)
```
All graph matching algorithms in `Gmatch4py work this way:
* Each algorithm is associated with an object, each object having its specific parameters. In this case, the parameters are the edit costs (delete a vertex, add a vertex, ...)
* Each object is associated with a `compare()` function with two parameters. First parameter is **a list of the graphs** you want to **compare**, i.e. measure the distance/similarity (depends on the algorithm). Then, you can specify a sample of graphs to be compared to all the other graphs. To this end, the second parameter should be **a list containing the indices** of these graphs (based on the first parameter list). If you rather compute the distance/similarity **between all graphs**, just use the `None` value.
```{python}
ged=GraphEditDistance(1,1,1,1) # all edit costs are equal to 1
result=ged.compare([g1,g2],None)
print(result)
```
The output is a similarity/distance matrix :
```
Out[10]:
array([[0., 7.],
[7., 0.]])
```
This output result is "raw", if you wish to have normalized results in terms of distance (or similarity) you can use :
```
ged.similarity(result)
# or
ged.distance(result)
```
* An array containing the graphs to compare
* An array containing indexes of graph you want to compare. Set to `None`, if you want to
measure the similarity/distance between every graphs.
