python3 pandas 中的时间轮

Question

如何使用 logon/logoff 个事件时间创建类似于下面的时间轮？专门寻找以时间轮方式关联与星期几相关的平均 login/logoff 时间？下面的图片是一个示例，但我正在寻找全天候的时间，一周中的几天，现在的时间在图片中。我有 python 可供我使用和包含登录时间的数据集。我还想将颜色与用户类型相关联，例如管理员与普通用户或类似性质的用户。关于如何实现这一点的任何想法都会很棒。

下面是 pandas 数据框

中的一些示例数据

df:

TimeGenerated        EventID  Username  Message
2012-04-01 00:00:13  4624     Matthew   This guy logged onto the computer for the first time today
2012-04-01 00:00:14  4624     Matthew   This guy authenticated for some stuff 
2012-04-01 00:00:15  4624     Adam      This guy logged onto the computer for the first time today
2012-04-01 00:00:16  4624     James     This guy logged onto the computer for the first time today
2012-04-01 12:00:17  4624     Adam      This guy authenticated for some stuff
2012-04-01 12:00:18  4625     James     This guy logged off the computer for the last time today
2012-04-01 12:00:19  4624     Adam      This guy authenticated for some stuff
2012-04-01 12:00:20  4625     Adam      This guy logged off the computer for the last time today 
2012-04-01 12:00:21  4625     Matthew   This guy logged off the computer for the last time today

Answer 1

基本上，您需要执行 2 个不相交的任务：

创建一个频率table 您将要可视化
定义一个函数来可视化给定的 table

对于第一个任务，我假设您只需要一个包含工作日和时间的数据透视表 table。我随机生成一个：

import pandas as pd
import matplotlib.pyplot as plt
import numpy as np
import pandas as pd
import matplotlib as mpl
import matplotlib.cm as cm
import calendar

# generate the table with timestamps
np.random.seed(1)
times = pd.Series(pd.to_datetime("Nov 1 '16 at 0:42") + pd.to_timedelta(np.random.rand(10000)*60*24*40, unit='m'))
# generate counts of each (weekday, hour)
data = pd.crosstab(times.dt.weekday, times.dt.hour.apply(lambda x: '{:02d}:00'.format(x))).fillna(0)
data.index = [calendar.day_name[i][0:3] for i in data.index]
print(data.T)

看起来像这样。每个数字都是此时登录的计数器：

       Mon  Tue  Wed  Thu  Fri  Sat  Sun
col_0                                   
00:00   55   56   67   60   60   62   45
01:00   51   65   70   65   60   59   40
02:00   47   76   67   68   61   63   51
....

现在，让我们为这个table画个轮子吧！它将由多个饼图组成：

# make a heatmap building function 
def pie_heatmap(table, cmap=cm.hot, vmin=None, vmax=None,inner_r=0.25, pie_args={}):
    n, m = table.shape
    vmin= table.min().min() if vmin is None else vmin
    vmax= table.max().max() if vmax is None else vmax

    centre_circle = plt.Circle((0,0),inner_r,edgecolor='black',facecolor='white',fill=True,linewidth=0.25)
    plt.gcf().gca().add_artist(centre_circle)
    norm = mpl.colors.Normalize(vmin=vmin, vmax=vmax)
    cmapper = cm.ScalarMappable(norm=norm, cmap=cmap)
    for i, (row_name, row) in enumerate(table.iterrows()):
        labels = None if i > 0 else table.columns
        wedges = plt.pie([1] * m,radius=inner_r+float(n-i)/n, colors=[cmapper.to_rgba(x) for x in row.values], 
            labels=labels, startangle=90, counterclock=False, wedgeprops={'linewidth':-1}, **pie_args)
        plt.setp(wedges[0], edgecolor='white',linewidth=1.5)
        wedges = plt.pie([1], radius=inner_r+float(n-i-1)/n, colors=['w'], labels=[row_name], startangle=-90, wedgeprops={'linewidth':0})
        plt.setp(wedges[0], edgecolor='white',linewidth=1.5)



plt.figure(figsize=(8,8))
pie_heatmap(data, vmin=-20,vmax=80,inner_r=0.2)

plt.show();

希望对你有帮助。

Answer 2

根据@DavidDale 的回答生成数据，可以在极轴上绘制 table 的 pcolormesh 图。这将直接给出所需的情节。

import pandas as pd
import matplotlib.pyplot as plt
import numpy as np
import calendar

# generate the table with timestamps
np.random.seed(1)
times = pd.Series(pd.to_datetime("Nov 1 '16 at 0:42") + 
                  pd.to_timedelta(np.random.rand(10000)*60*24*40, unit='m'))
# generate counts of each (weekday, hour)
data = pd.crosstab(times.dt.weekday, 
                   times.dt.hour.apply(lambda x: '{:02d}:00'.format(x))).fillna(0)
data.index = [calendar.day_name[i][0:3] for i in data.index]
data = data.T

# produce polar plot
fig, ax = plt.subplots(subplot_kw=dict(projection='polar'))
ax.set_theta_zero_location("N")
ax.set_theta_direction(-1)

# plot data
theta, r = np.meshgrid(np.linspace(0,2*np.pi,len(data)+1),np.arange(len(data.columns)+1))
ax.pcolormesh(theta,r,data.T.values, cmap="Reds")

# set ticklabels
pos,step = np.linspace(0,2*np.pi,len(data),endpoint=False, retstep=True)
pos += step/2.
ax.set_xticks(pos)
ax.set_xticklabels(data.index)

ax.set_yticks(np.arange(len(data.columns)))
ax.set_yticklabels(data.columns)
plt.show()

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