我试图在这个数据集上创建一个有向图:
ID Link_to Label Date Size
0 mary NaN 0 2020-01-23 1
1 Julie Mirk 1 2020-02-27 12
1 Julie Mark 1 2020-02-27 12
1 Julie Sarah 1 2020-02-27 12
1 Chris Mirk 1 2020-01-26 12
... ... ... ... ... ... ...
50 Mirk Chris 0 2020-04-29 4
51 Mark NaN 0 2020-04-29 3
52 Greg NaN 0 2020-04-27 2
53 Luke Matt 0 2020-04-08 1
54 Sarah James 0 2020-04-01 1
为了用上面的数据创建一个无向图,我做了:G = nx.from_pandas_edgelist(df, 'ID', 'Link_to')
d = dict(df.drop_duplicates(subset=['ID'])[['ID']]
.to_numpy().tolist())
nodes = G.nodes()
plt.figure(figsize=(20,33))
pos = nx.draw(G, with_labels=True,
nodelist=nodes,
node_color=[d.get(i,'lightgreen') for i in nodes],
node_size=1000)
我想在图中添加日期信息,以创建一个有向图:日期最早的ID是源。例如: Julie 和 Mirk 链接在一起:应该添加从 Julie 到 Mirk 的定向链接。
另一个例子:Chris 和 Mirk 彼此相连。但是,由于与 ID 相比,Chris 的日期最早,因此将 Mirk 与 Chris 联系起来。如果两个 ID 相互链接并且它们具有相同的日期,则它们应该有一个箭头(双向)。
我怎样才能弄清楚如何在我的图表中添加日期信息?
最佳答案
根据您提供的数据(我添加了额外的行 Sarah -> Julie
与相同的 Date
):
s = """index ID Link_to Label Date Size
0 mary NaN 0 2020-01-23 1
1 Julie Mirk 1 2020-02-27 12
1 Julie Mark 1 2020-02-27 12
1 Julie Sarah 1 2020-02-27 12
1 Sarah Julie 1 2020-02-27 12
1 Chris Mirk 1 2020-01-26 12
50 Mirk Chris 0 2020-04-29 4
51 Mark NaN 0 2020-04-29 3
52 Greg NaN 0 2020-04-27 2
53 Luke Matt 0 2020-04-08 1
54 Sarah James 0 2020-04-01 1"""
df = pd.read_csv(io.StringIO(re.sub("[ ]+", ",", s)), parse_dates=['Date'])
df = df.dropna().drop(["index", "Label", "Size"], axis=1)
我们有以下数据集: ID Link_to Date
1 Julie Mirk 2020-02-27
2 Julie Mark 2020-02-27
3 Julie Sarah 2020-02-27
4 Sarah Julie 2020-02-27
5 Chris Mirk 2020-01-26
6 Mirk Chris 2020-04-29
9 Luke Matt 2020-04-08
10 Sarah James 2020-04-01
我们可以将数据帧与其自身合并以检查应保留哪种组合:c = df.merge(df, how='left', left_on=['ID', 'Link_to'], right_on=['Link_to', 'ID'], suffixes=('', '_r'))
c['Date_r'] = c['Date_r'].fillna(c['Date'])
假设你想保持最早的关系(例如: Chris -> Mirk
而不是 Mirk -> Chris
)那么标准是关于:c['keep'] = c['Date'] <= c['Date_r']
如果您打算相反,只需将不等式关系更改为 >=
.结果如下:
ID Link_to Date ID_r Link_to_r Date_r keep
0 Julie Mirk 2020-02-27 NaN NaN 2020-02-27 True
1 Julie Mark 2020-02-27 NaN NaN 2020-02-27 True
2 Julie Sarah 2020-02-27 Sarah Julie 2020-02-27 True
3 Sarah Julie 2020-02-27 Julie Sarah 2020-02-27 True
4 Chris Mirk 2020-01-26 Mirk Chris 2020-04-29 True
5 Mirk Chris 2020-04-29 Chris Mirk 2020-01-26 False
6 Luke Matt 2020-04-08 NaN NaN 2020-04-08 True
7 Sarah James 2020-04-01 NaN NaN 2020-04-01 True
构建有向图非常简单:c = c.loc[c['keep'], :]
G = nx.from_pandas_edgelist(c, 'ID', 'Link_to', create_using=nx.DiGraph)
最终结果大约是:nx.draw_networkx(G)
它似乎符合您的预期输出:
关于python - 如何创建有向图?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/63793230/