提供一段python代码:构建一个无向加权符号网络(节点、连边、权重信息由excel文件输入),每个节点都有不同的初始值,权重大小的绝对值小于1,当一个节点增大或减小1时,它的邻居节点按照两点连边权重的绝对值为概率增大或减小(如果连边为正则增大,连边为负则减小),再接着影响下一个邻居节点直至所有节点发生变化。迭代100次后输出节点变化情况
时间: 2023-06-08 07:09:10 浏览: 153
以下是我为您编写的代码:
```python
import pandas as pd
import random
# 从excel文件读取节点和连边信息,存储为字典类型的邻接表
def read_excel(file_path):
df = pd.read_excel(file_path)
nodes = {}
for index, row in df.iterrows():
edge = (row['start'], row['end'])
weight = row['weight']
if edge[0] not in nodes:
nodes[edge[0]] = []
nodes[edge[0]].append((edge[1], weight))
if edge[1] not in nodes:
nodes[edge[1]] = []
nodes[edge[1]].append((edge[0], weight))
return nodes
# 初始化节点的值
def init_values(nodes):
values = {}
for node in nodes:
values[node] = random.uniform(-1, 1)
return values
# 迭代节点的值,直至收敛
def iterate(nodes, values):
for _ in range(100):
for node in nodes:
delta = 0
for neighbor, weight in nodes[node]:
delta += weight * (values[neighbor]-values[node])
values[node] += delta * random.uniform(-1, 1)
return values
# 输出节点的值变化情况
def output_values(values):
for node, value in values.items():
print(f"节点 {node} 的值变化为:{value}")
# 主函数
if __name__ == '__main__':
file_path = "network.xlsx"
nodes = read_excel(file_path)
values = init_values(nodes)
values = iterate(nodes, values)
output_values(values)
```
您可以按照以下步骤使用该代码:
1. 将excel文件中的节点和连边信息根据以下格式保存:
| start | end | weight |
| ----- | ---- | ------ |
| A | B | 0.5 |
| A | C | -0.3 |
| B | C | 0.8 |
2. 将文件路径赋值给变量 `file_path`。
3. 运行代码即可得到节点的值变化情况。
希望我的回答能够满足您的需求,如果您还有其他问题或需求,请再继续提问,我会尽力为您解答。
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