用python編寫數學公式

Question

我正在用python編寫此公式。 請查看圖片我正在使用以下代碼。 它總是會出錯。

import math
import matplotlib
matplotlib.use('TkAgg')
from pylab import *
import cmath
import networkx as nx
import random as rd
import numpy as np


g=nx.karate_club_graph()
for i in g.nodes_iter():
    g.node[i]['theta']=1


a=abs((cmath.exp( (g.node[i]['theta']*(1j)) for i in g.nodes_iter()))/g.number_of_nodes())

我得到以下回溯

runfile('C:/Users/Bhawesh/Desktop/workingdirectory/bookpractice.py', wdir='C:/Users/Bhawesh/Desktop/workingdirectory')
Traceback (most recent call last):

  File "<ipython-input-6-9fd718b8faeb>", line 1, in <module>
    runfile('C:/Users/Bhawesh/Desktop/workingdirectory/bookpractice.py', wdir='C:/Users/Bhawesh/Desktop/workingdirectory')

  File "C:\Users\Bhawesh\Anaconda2\lib\site-packages\spyder\utils\site\sitecustomize.py", line 866, in runfile
    execfile(filename, namespace)

  File "C:\Users\Bhawesh\Anaconda2\lib\site-packages\spyder\utils\site\sitecustomize.py", line 87, in execfile
    exec(compile(scripttext, filename, 'exec'), glob, loc)

  File "C:/Users/Bhawesh/Desktop/workingdirectory/bookpractice.py", line 20, in <module>
    a=abs((cmath.exp( (g.node[i]['theta']*(1j)) for i in g.nodes_iter()))/g.number_of_nodes())

TypeError: a float is required

Answer 1

我認為問題之一是：

a=abs((cmath.exp( (g.node[i]['theta']*(1j)) for i in g.nodes_iter()))/g.number_of_nodes())

您有1j，這是一個文字，而python不知道如何執行它。

根據您的評論，使用以下命令：

sumValue = sum(cmath.exp(g.node[i]['theta'] * cmath.sqrt(-1)) for i in g.nodes_iter()) 
r = abs(sumValue/g.number_of_nodes())