如何向 stellargraph 数据集添加新边？

Question

I need to add some extra edges to Cora dataset using stellargraph. Is there ane way to add edges to the current dataset in stellargraph library?

import stellargraph as sg
dataset = sg.datasets.Cora()

For example in NetworkX, we can add some edges to the existing graph using add_edges_from(edgelist) .

Answer 1

I recently ran into a similar scenario and converting back-and-forth to networkx format was not possible. Specifically, since StellarGraph is supposed to be capable of storing graphs much larger than networkx , there will be a point at which converting would not be possible.

To get around this, I used the numpy loading capabilities of StellarGraph 1.2.1 .

With StellarGraph , you can dump the edge array with edge_arrays() into pandas , then concatenate any desired edges onto that. It is much lighter memory-wise, since pandas and StellarGraph both perform better than networkx .

Here is a short example:

import pandas as pd
from stellargraph import IndexedArray, StellarGraph

#### original data / graph

nodes = IndexedArray(index=['a', 'b', 'c', 'd'])
original_edges = pd.DataFrame(
    {
        'source' : [0, 1, 2, 3, 0],
        'target' : [1, 2, 3, 0, 2]
    }
)
original_graph = StellarGraph(
    nodes, 
    original_edges
)

#### new data

new_edges = pd.DataFrame(
    {
        'source' : [3, 3],
        'target' : [1, 2]
    }
)

#### new graph

new_graph = StellarGraph(
    nodes, 
    pd.concat(
        [
            original_edges,
            new_edges
        ],
        ignore_index=True
    )
)

Answer 2

You can't do it directly from stellargraph since version 0.9. You'll have to use .to.networkx() to convert it back to.networkX format, add you edges and then convert it back to stellargraph.

from stellargraph import StellarGraph
import networkx as nx

g = StellarGraph.to_networkx(dataset)
g.add_edges_from(edgelist)
new_dataset = StellarGraph.from_networkx(g)