当时间转换为timedelta64时，Python matplotlib.pyplot正在绘制不同的图

Question

我有一个要显示加速度计数据的数据。但是，当我使用熊猫将时间从对象转换为timedelta时，它显示了不同的图形。我该怎么做才能正确绘制数据。

import pandas as pd
import matplotlib.pyplot as plt
df = pd.read_json("Right_191018_10-51-15_Eating_Floor_FrenchToast_ForkKnifeHand.json")
df[['Date','Time','GMT']] = df['loggingTime'].str.split(' ',expand=True)
dfright=pd.DataFrame({
    'X':df['accelerometerAccelerationX'],
    'Y':df['accelerometerAccelerationY'],
    'Z':df['accelerometerAccelerationZ'], 
    'Time':df['Time']
          })
print(dfright.dtypes)
plt.figure(figsize=(20,10))
plt.figtext('.5','.99','Acelrometer Data',fontsize=18,ha='center')

x,=plt.plot(
    dfright['Time'],
             dfright['X'],
    label='x'
    )
plt.legend([x],['x'])
plt.xlabel('time ')
plt.ylabel('accelro')
plt.title('Right Hand')
plt.gca().xaxis.set_major_locator(plt.MaxNLocator(10))

dfright['Time']=pd.to_timedelta(dfright['Time'])
print(dfright.dtypes)
plt.figure(figsize=(20,10))
plt.figtext('.5','.99','Acelrometer Data',fontsize=18,ha='center')

x,=plt.plot(
    dfright['Time'],
             dfright['X'],
    label='x'
    )
 plt.legend([x],['x'])
 plt.xlabel('time ')
 plt.ylabel('accelro')
 plt.title('Right Hand')
 plt.gca().xaxis.set_major_locator(plt.MaxNLocator(10))

数据

            X         Y         Z          Time
0    0.187256 -0.113373 -0.978668  10:51:15.627
1    0.203720 -0.121597 -0.967041  10:51:15.645
2    0.210968 -0.117950 -0.956497  10:51:15.648
3    0.221909 -0.114548 -0.949478  10:51:15.651
4    0.231415 -0.108597 -0.939728  10:51:15.656
..        ...       ...       ...           ...
992  0.275085  0.186905 -0.960556  10:58:28.910
993  0.251862  0.170105 -0.967285  10:58:28.925
994  0.266571  0.177551 -0.969528  10:58:28.940
995  0.277298  0.194107 -0.974319  10:58:28.955
996  0.273453  0.204010 -0.980560  10:58:28.973

这里是转换为timedelta之前的dtype

X       float64 
Y       float64 
Z       float64 
Time     object 
dtype: object

这里是转换为timedelta后的dtype

            X         Y         Z            Time
0    0.187256 -0.113373 -0.978668 10:51:15.627000
1    0.203720 -0.121597 -0.967041 10:51:15.645000
2    0.210968 -0.117950 -0.956497 10:51:15.648000
3    0.221909 -0.114548 -0.949478 10:51:15.651000
4    0.231415 -0.108597 -0.939728 10:51:15.656000
..        ...       ...       ...             ...
992  0.275085  0.186905 -0.960556 10:58:28.910000
993  0.251862  0.170105 -0.967285 10:58:28.925000
994  0.266571  0.177551 -0.969528 10:58:28.940000
995  0.277298  0.194107 -0.974319 10:58:28.955000
996  0.273453  0.204010 -0.980560 10:58:28.973000
X               float64
Y               float64
Z               float64
Time    timedelta64[ns]
dtype: object

Answer 1

来自此主题converting a time string to seconds in python

timestr = '00:04:23'

ftr = [3600,60,1]

sum([a*b for a,b in zip(ftr, map(int,timestr.split(':')))])
Output is 263Sec.

您可以运行函数将字符串转换为s（需要对代码进行一些修改）

稍后，从第一个值中减去每个值，就完成了。