Python：从 dataframe 创建邻接矩阵
[英]Python: Creating an adjacency matrix from a dataframe
问题描述
I have the following data frame:
我有以下数据框：
Company Firm
125911 1
125911 2
32679 3
32679 5
32679 5
32679 8
32679 10
32679 12
43805 14
67734 8
67734 9
67734 10
67734 10
67734 11
67734 12
67734 13
74240 4
74240 6
74240 7
Where basically the firm makes an investment into the company at a specific year which in this case is the same year for all companies.基本上，公司在特定年份对公司进行投资，在这种情况下，所有公司都是同一年。 What I want to do in python is to create a simple adjacency matrix with only 0's and 1's.我想在 python 中做的是创建一个只有 0 和 1 的简单邻接矩阵。 1 if two firms has made an investment into the same company. 1 如果两家公司对同一家公司进行了投资。 So even if firm 10 and 8 for example have invested in two different firms at the same it will still be a 1. The resulting matrix I am looking for looks like:因此，即使公司 10 和 8 例如同时投资了两家不同的公司，它仍然是 1。我正在寻找的结果矩阵如下所示：
Firm 1 2 3 4 5 6 7 8 9 10 11 12 13 14
1 0 1 0 0 0 0 0 0 0 0 0 0 0 0
2 1 0 0 0 0 0 0 0 0 0 0 0 0 0
3 0 0 0 0 1 0 0 1 0 1 0 1 0 0
4 0 0 0 0 0 1 1 0 0 0 0 0 0 0
5 0 0 1 0 0 0 0 1 0 1 0 1 0 0
6 0 0 0 1 0 0 1 0 0 0 0 0 0 0
7 0 0 0 1 0 1 0 0 0 0 0 0 0 0
8 0 0 1 0 1 0 0 0 1 1 1 1 1 0
9 0 0 0 0 0 0 0 1 0 1 1 1 1 0
10 0 0 1 0 1 0 0 1 1 0 1 1 1 0
11 0 0 0 0 0 0 0 1 1 1 0 1 1 0
12 0 0 1 0 1 0 0 1 1 1 1 0 1 0
13 0 0 0 0 0 0 0 1 1 1 1 1 0 0
14 0 0 0 0 0 0 0 0 0 0 0 0 0 0
I have seen similar questions where you can use crosstab , however in that case each company will only have one row with all the firms in different columns instead.我见过类似的问题，您可以在其中使用crosstab ，但是在这种情况下，每家公司将只有一行，所有公司都位于不同的列中。 So I am wondering what the best and most efficient way to tackle this specific problem is?所以我想知道解决这个特定问题的最佳和最有效的方法是什么？ Any help is greatly appreciated.任何帮助是极大的赞赏。
2 个解决方案
解决方案1
2 已采纳 2021-05-04 19:12:12
dfs = []
for s in df.groupby("Company").agg(list).values:
dfs.append(pd.DataFrame(index=set(s[0]), columns=set(s[0])).fillna(1))
out = pd.concat(dfs).groupby(level=0).sum().gt(0).astype(int)
np.fill_diagonal(out.values, 0)
print(out)
Prints:印刷：
1 2 3 4 5 6 7 8 9 10 11 12 13 14
1 0 1 0 0 0 0 0 0 0 0 0 0 0 0
2 1 0 0 0 0 0 0 0 0 0 0 0 0 0
3 0 0 0 0 1 0 0 1 0 1 0 1 0 0
4 0 0 0 0 0 1 1 0 0 0 0 0 0 0
5 0 0 1 0 0 0 0 1 0 1 0 1 0 0
6 0 0 0 1 0 0 1 0 0 0 0 0 0 0
7 0 0 0 1 0 1 0 0 0 0 0 0 0 0
8 0 0 1 0 1 0 0 0 1 1 1 1 1 0
9 0 0 0 0 0 0 0 1 0 1 1 1 1 0
10 0 0 1 0 1 0 0 1 1 0 1 1 1 0
11 0 0 0 0 0 0 0 1 1 1 0 1 1 0
12 0 0 1 0 1 0 0 1 1 1 1 0 1 0
13 0 0 0 0 0 0 0 1 1 1 1 1 0 0
14 0 0 0 0 0 0 0 0 0 0 0 0 0 0
解决方案2
0 2021-05-04 18:07:34
dfm = df.merge(df, on="Company").query("Firm_x != Firm_y")
out = pd.crosstab(dfm['Firm_x'], dfm['Firm_y'])
>>> out
Firm_y 1 2 3 4 5 6 7 8 9 10 11 12 13 14
Firm_x
1 1 0 0 0 0 0 0 0 0 0 0 0 0 0
2 0 1 0 0 0 0 0 0 0 0 0 0 0 0
3 0 0 1 0 0 0 0 0 0 0 0 0 0 0
4 0 0 0 1 0 0 0 0 0 0 0 0 0 0
5 0 0 0 0 4 0 0 0 0 0 0 0 0 0
6 0 0 0 0 0 1 0 0 0 0 0 0 0 0
7 0 0 0 0 0 0 1 0 0 0 0 0 0 0
8 0 0 0 0 0 0 0 2 0 0 0 0 0 0
9 0 0 0 0 0 0 0 0 1 0 0 0 0 0
10 0 0 0 0 0 0 0 0 0 5 0 0 0 0
11 0 0 0 0 0 0 0 0 0 0 1 0 0 0
12 0 0 0 0 0 0 0 0 0 0 0 2 0 0
13 0 0 0 0 0 0 0 0 0 0 0 0 1 0
14 0 0 0 0 0 0 0 0 0 0 0 0 0 1
声明:本站的技术帖子网页，遵循CC BY-SA 4.0协议，如果您需要转载，请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.