Python时间序列分析
Posted
tags:
篇首语:本文由小常识网(cha138.com)小编为大家整理,主要介绍了Python时间序列分析相关的知识,希望对你有一定的参考价值。
时间序列与时间序列分析
在生产和科学研究中,对某一个或者一组变量 进行观察测量,将在一系列时刻所得到的离散数字组成的序列集合,称之为时间序列。
时间序列分析是根据系统观察得到的时间序列数据,通过曲线拟合和参数估计来建立数学模型的理论和方法。时间序列分析常用于国民宏观经济控制、市场潜力预测、气象预测、农作物害虫灾害预报等各个方面。
Pandas生成时间序列:
import pandas as pd import numpy as np
时间序列
- 时间戳(timestamp)
- 固定周期(period)
- 时间间隔(interval)
date_range
- 可以指定开始时间与周期
- H:小时
- D:天
- M:月
# TIMES的几种书写方式 #2016 Jul 1; 7/1/2016; 1/7/2016 ;2016-07-01; 2016/07/01 rng = pd.date_range(\'2016-07-01\', periods = 10, freq = \'3D\')#不传freq则默认是D rng
结果:
DatetimeIndex([\'2016-07-01\', \'2016-07-04\', \'2016-07-07\', \'2016-07-10\', \'2016-07-13\', \'2016-07-16\', \'2016-07-19\', \'2016-07-22\', \'2016-07-25\', \'2016-07-28\'], dtype=\'datetime64[ns]\', freq=\'3D\')
time=pd.Series(np.random.randn(20), index=pd.date_range(dt.datetime(2016,1,1),periods=20)) print(time) #结果: 2016-01-01 -0.129379 2016-01-02 0.164480 2016-01-03 -0.639117 2016-01-04 -0.427224 2016-01-05 2.055133 2016-01-06 1.116075 2016-01-07 0.357426 2016-01-08 0.274249 2016-01-09 0.834405 2016-01-10 -0.005444 2016-01-11 -0.134409 2016-01-12 0.249318 2016-01-13 -0.297842 2016-01-14 -0.128514 2016-01-15 0.063690 2016-01-16 -2.246031 2016-01-17 0.359552 2016-01-18 0.383030 2016-01-19 0.402717 2016-01-20 -0.694068 Freq: D, dtype: float64
truncate过滤
time.truncate(before=\'2016-1-10\')#1月10之前的都被过滤掉了
结果:
2016-01-10 -0.005444
2016-01-11 -0.134409
2016-01-12 0.249318
2016-01-13 -0.297842
2016-01-14 -0.128514
2016-01-15 0.063690
2016-01-16 -2.246031
2016-01-17 0.359552
2016-01-18 0.383030
2016-01-19 0.402717
2016-01-20 -0.694068
Freq: D, dtype: float64
time.truncate(after=\'2016-1-10\')#1月10之后的都被过滤掉了 #结果: 2016-01-01 -0.129379 2016-01-02 0.164480 2016-01-03 -0.639117 2016-01-04 -0.427224 2016-01-05 2.055133 2016-01-06 1.116075 2016-01-07 0.357426 2016-01-08 0.274249 2016-01-09 0.834405 2016-01-10 -0.005444 Freq: D, dtype: float64
print(time[\'2016-01-15\'])#0.063690487247 print(time[\'2016-01-15\':\'2016-01-20\']) 结果: 2016-01-15 0.063690 2016-01-16 -2.246031 2016-01-17 0.359552 2016-01-18 0.383030 2016-01-19 0.402717 2016-01-20 -0.694068 Freq: D, dtype: float64 data=pd.date_range(\'2010-01-01\',\'2011-01-01\',freq=\'M\') print(data) #结果: DatetimeIndex([\'2010-01-31\', \'2010-02-28\', \'2010-03-31\', \'2010-04-30\', \'2010-05-31\', \'2010-06-30\', \'2010-07-31\', \'2010-08-31\', \'2010-09-30\', \'2010-10-31\', \'2010-11-30\', \'2010-12-31\'], dtype=\'datetime64[ns]\', freq=\'M\')
#时间戳 pd.Timestamp(\'2016-07-10\')#Timestamp(\'2016-07-10 00:00:00\') # 可以指定更多细节 pd.Timestamp(\'2016-07-10 10\')#Timestamp(\'2016-07-10 10:00:00\') pd.Timestamp(\'2016-07-10 10:15\')#Timestamp(\'2016-07-10 10:15:00\') # How much detail can you add? t = pd.Timestamp(\'2016-07-10 10:15\') # 时间区间 pd.Period(\'2016-01\')#Period(\'2016-01\', \'M\') pd.Period(\'2016-01-01\')#Period(\'2016-01-01\', \'D\') # TIME OFFSETS pd.Timedelta(\'1 day\')#Timedelta(\'1 days 00:00:00\') pd.Period(\'2016-01-01 10:10\') + pd.Timedelta(\'1 day\')#Period(\'2016-01-02 10:10\', \'T\') pd.Timestamp(\'2016-01-01 10:10\') + pd.Timedelta(\'1 day\')#Timestamp(\'2016-01-02 10:10:00\') pd.Timestamp(\'2016-01-01 10:10\') + pd.Timedelta(\'15 ns\')#Timestamp(\'2016-01-01 10:10:00.000000015\') p1 = pd.period_range(\'2016-01-01 10:10\', freq = \'25H\', periods = 10) p2 = pd.period_range(\'2016-01-01 10:10\', freq = \'1D1H\', periods = 10) p1 p2 结果: PeriodIndex([\'2016-01-01 10:00\', \'2016-01-02 11:00\', \'2016-01-03 12:00\', \'2016-01-04 13:00\', \'2016-01-05 14:00\', \'2016-01-06 15:00\', \'2016-01-07 16:00\', \'2016-01-08 17:00\', \'2016-01-09 18:00\', \'2016-01-10 19:00\'], dtype=\'period[25H]\', freq=\'25H\') PeriodIndex([\'2016-01-01 10:00\', \'2016-01-02 11:00\', \'2016-01-03 12:00\', \'2016-01-04 13:00\', \'2016-01-05 14:00\', \'2016-01-06 15:00\', \'2016-01-07 16:00\', \'2016-01-08 17:00\', \'2016-01-09 18:00\', \'2016-01-10 19:00\'], dtype=\'period[25H]\', freq=\'25H\') # 指定索引 rng = pd.date_range(\'2016 Jul 1\', periods = 10, freq = \'D\') rng pd.Series(range(len(rng)), index = rng) 结果: 2016-07-01 0 2016-07-02 1 2016-07-03 2 2016-07-04 3 2016-07-05 4 2016-07-06 5 2016-07-07 6 2016-07-08 7 2016-07-09 8 2016-07-10 9 Freq: D, dtype: int32 periods = [pd.Period(\'2016-01\'), pd.Period(\'2016-02\'), pd.Period(\'2016-03\')] ts = pd.Series(np.random.randn(len(periods)), index = periods) ts 结果: 2016-01 -0.015837 2016-02 -0.923463 2016-03 -0.485212 Freq: M, dtype: float64 type(ts.index)#pandas.core.indexes.period.PeriodIndex # 时间戳和时间周期可以转换 ts = pd.Series(range(10), pd.date_range(\'07-10-16 8:00\', periods = 10, freq = \'H\')) ts 结果: 2016-07-10 08:00:00 0 2016-07-10 09:00:00 1 2016-07-10 10:00:00 2 2016-07-10 11:00:00 3 2016-07-10 12:00:00 4 2016-07-10 13:00:00 5 2016-07-10 14:00:00 6 2016-07-10 15:00:00 7 2016-07-10 16:00:00 8 2016-07-10 17:00:00 9 Freq: H, dtype: int32 ts_period = ts.to_period() ts_period 结果: 2016-07-10 08:00 0 2016-07-10 09:00 1 2016-07-10 10:00 2 2016-07-10 11:00 3 2016-07-10 12:00 4 2016-07-10 13:00 5 2016-07-10 14:00 6 2016-07-10 15:00 7 2016-07-10 16:00 8 2016-07-10 17:00 9 Freq: H, dtype: int32 时间周期与时间戳的区别 ts_period[\'2016-07-10 08:30\':\'2016-07-10 11:45\'] #时间周期包含08:00 结果: 2016-07-10 08:00 0 2016-07-10 09:00 1 2016-07-10 10:00 2 2016-07-10 11:00 3 Freq: H, dtype: int32 ts[\'2016-07-10 08:30\':\'2016-07-10 11:45\'] #时间戳不包含08:30 #结果: 2016-07-10 09:00:00 1 2016-07-10 10:00:00 2 2016-07-10 11:00:00 3 Freq: H, dtype: int32
数据重采样:
- 时间数据由一个频率转换到另一个频率
- 降采样
- 升采样
import pandas as pd import numpy as np rng = pd.date_range(\'1/1/2011\', periods=90, freq=\'D\')#数据按天 ts = pd.Series(np.random.randn(len(rng)), index=rng) ts.head() 结果: 2011-01-01 -1.025562 2011-01-02 0.410895 2011-01-03 0.660311 2011-01-04 0.710293 2011-01-05 0.444985 Freq: D, dtype: float64 ts.resample(\'M\').sum()#数据降采样,降为月,指标是求和,也可以平均,自己指定 结果: 2011-01-31 2.510102 2011-02-28 0.583209 2011-03-31 2.749411 Freq: M, dtype: float64 ts.resample(\'3D\').sum()#数据降采样,降为3天 结果: 2011-01-01 0.045643 2011-01-04 -2.255206 2011-01-07 0.571142 2011-01-10 0.835032 2011-01-13 -0.396766 2011-01-16 -1.156253 2011-01-19 -1.286884 2011-01-22 2.883952 2011-01-25 1.566908 2011-01-28 1.435563 2011-01-31 0.311565 2011-02-03 -2.541235 2011-02-06 0.317075 2011-02-09 1.598877 2011-02-12 -1.950509 2011-02-15 2.928312 2011-02-18 -0.733715 2011-02-21 1.674817 2011-02-24 -2.078872 2011-02-27 2.172320 2011-03-02 -2.022104 2011-03-05 -0.070356 2011-03-08 1.276671 2011-03-11 -2.835132 2011-03-14 -1.384113 2011-03-17 1.517565 2011-03-20 -0.550406 2011-03-23 0.773430 2011-03-26 2.244319 2011-03-29 2.951082 Freq: 3D, dtype: float64 day3Ts = ts.resample(\'3D\').mean() day3Ts 结果: 2011-01-01 0.015214 2011-01-04 -0.751735 2011-01-07 0.190381 2011-01-10 0.278344 2011-01-13 -0.132255 2011-01-16 -0.385418 2011-01-19 -0.428961 2011-01-22 0.961317 2011-01-25 0.522303 2011-01-28 0.478521 2011-01-31 0.103855 2011-02-03 -0.847078 2011-02-06 0.105692 2011-02-09 0.532959 2011-02-12 -0.650170 2011-02-15 0.976104 2011-02-18 -0.244572 2011-02-21 0.558272 2011-02-24 -0.692957 2011-02-27 0.724107 2011-03-02 -0.674035 2011-03-05 -0.023452 2011-03-08 0.425557 2011-03-11 -0.945044 2011-03-14 -0.461371 2011-03-17 0.505855 2011-03-20 -0.183469 2011-03-23 0.257810 2011-03-26 0.748106 2011-03-29 0.983694 Freq: 3D, dtype: float64 print(day3Ts.resample(\'D\').asfreq())#升采样,要进行插值 结果: 2011-01-01 0.015214 2011-01-02 NaN 2011-01-03 NaN 2011-01-04 -0.751735 2011-01-05 NaN 2011-01-06 NaN 2011-01-07 0.190381 2011-01-08 NaN 2011-01-09 NaN 2011-01-10 0.278344 2011-01-11 NaN 2011-01-12 NaN 2011-01-13 -0.132255 2011-01-14 NaN 2011-01-15 NaN 2011-01-16 -0.385418 2011-01-17 NaN 2011-01-18 NaN 2011-01-19 -0.428961 2011-01-20 NaN 2011-01-21 NaN 2011-01-22 0.961317 2011-01-23 NaN 2011-01-24 NaN 2011-01-25 0.522303 2011-01-26 NaN 2011-01-27 NaN 2011-01-28 0.478521 2011-01-29 NaN 2011-01-30 NaN ... 2011-02-28 NaN 2011-03-01 NaN 2011-03-02 -0.674035 2011-03-03 NaN 2011-03-04 NaN 2011-03-05 -0.023452 2011-03-06 NaN 2011-03-07 NaN 2011-03-08 0.425557 2011-03-09 NaN 2011-03-10 NaN 2011-03-11 -0.945044 2011-03-12 NaN 2011-03-13 NaN 2011-03-14 -0.461371 2011-03-15 NaN 2011-03-16 NaN 2011-03-17 0.505855 2011-03-18 NaN 2011-03-19 NaN 2011-03-20 -0.183469 2011-03-21 NaN 2011-03-22 NaN 2011-03-23 0.257810 2011-03-24 NaN 2011-03-25 NaN 2011-03-26 0.748106 2011-03-27 NaN 2011-03-28 NaN 2011-03-29 0.983694 Freq: D, Length: 88, dtype: float64
插值方法:
- ffill 空值取前面的值
- bfill 空值取后面的值
- interpolate 线性取值
day3Ts.resample(\'D\').ffill(1) 结果: 2011-01-01 0.015214 2011-01-02 0.015214 2011-01-03 NaN 2011-01-04 -0.751735 2011-01-05 -0.751735 2011-01-06 NaN 2011-01-07 0.190381 2011-01-08 0.190381 2011-01-09 NaN 2011-01-10 0.278344 2011-01-11 0.278344 2011-01-12 NaN 2011-01-13 -0.132255 2011-01-14 -0.132255 2011-01-15 NaN 2011-01-16 -0.385418 2011-01-17 -0.385418 2011-01-18 NaN 2011-01-19 -0.428961 2011-01-20 -0.428961 2011-01-21 NaN 2011-01-22 0.961317 2011-01-23 0.961317 2011-01-24 NaN 2011-01-25 0.522303 2011-01-26 0.522303 2011-01-27 NaN 2011-01-28 0.478521 2011-01-29 0.478521 2011-01-30 NaN ... 2011-02-28 0.724107 2011-03-01 NaN 2011-03-02 -0.674035 2011-03-03 -0.674035 2011-03-04 NaN 2011-03-05 -0.023452 2011-03-06 -0.023452 2011-03-07 NaN 2011-03-08 0.425557 2011-03-09 0.425557 2011-03-10 NaN 2011-03-11 -0.945044 2011-03-12 -0.945044 2011-03-13 NaN 2011-03-14 -0.461371 2011-03-15 -0.461371 2011-03-16 NaN 2011-03-17 0.505855 2011-03-18 0.505855 2011-03-19 NaN 2011-03-20 -0.183469 2011-03-21 -0.183469 2011-03-22 NaN 2011-03-23 0.257810 2011-03-24 0.257810 2011-03-25 NaN 2011-03-26 0.748106 2011-03-27 0.748106 2011-03-28 NaN 2011-03-29 0.983694 Freq: D, Length: 88, dtype: float64 day3Ts.resample(\'D\').bfill(1) 结果: 2011-01-01 0.015214 2011-01-02 NaN 2011-01-03 -0.751735 2011-01-04 -0.751735 2011-01-05 NaN 2011-01-06 0.190381 2011-01-07 0.190381 2011-01-08 NaN 2011-01-09 0.278344 2011-01-10 0.278344 2011-01-11 NaN 2011-01-12 -0.132255 2011-01-13 -0.132255 2011-01-14 NaN 2011-01-15 -0.385418 2011-01-16 -0.385418 2011-01-17 NaN 2011-01-18 -0.428961 2011-01-19 -0.428961 2011-01-20 NaN 2011-01-21 0.961317 2011-01-22 0.961317 2011-01-23 NaN 2011-01-24 0.522303 2011-01-25 0.522303 2011-01-26 NaN 2011-01-27 0.478521 2011-01-28 0.478521 2011-01-29 NaN 2011-01-30 0.103855 ... 2011-02-28 NaN 2011-03-01 -0.674035 2011-03-02 -0.674035 2011-03-03 NaN 2011-03-04 -0.023452 2011-03-05 -0.023452 2011-03-06 NaN 2011-03-07 0.425557 2011-03-08 0.425557 2011-03-09 NaN 2011-03-10 -0.945044 2011-03-11 -0.945044 2011-03-12 NaN 2011-03-13 -0.461371 2011-03-14 -0.461371 2011-03-15 NaN 2011-03-16 0.505855 2011-03-17 0.505855 2011-03-18 NaN 2011-03-19 -0.183469 2011-03-20 -0.183469 2011-03-21 NaN 2011-03-22 0.257810 2011-03-23 0.257810 2011-03-24 NaN 2011-03-25 0.748106 2011-03-26 0.748106 2011-03-27 NaN 2011-03-28 0.983694 2011-03-29 0.983694 Freq: D, Length: 88, dtype: float64 day3Ts.resample(\'D\').interpolate(\'linear\')#线性拟合填充 结果: 2011-01-01 0.015214 2011-01-02 -0.240435 2011-01-03 -0.496085 2011-01-04 -0.751735 2011-01-05 -0.437697 2011-01-06 -0.123658 2011-01-07 0.190381 2011-01-08 0.219702 2011-01-09 0.249023 2011-01-10 0.278344 2011-01-11 0.141478 2011-01-12 0.004611 2011-01-13 -0.132255 2011-01-14 -0.216643 2011-01-15 -0.301030 2011-01-16 -0.385418 2011-01-17 -0.399932 2011-01-18 -0.414447 2011-01-19 -0.428961 2011-01-20 0.034465 2011-01-21 0.497891 2011-01-22 0.961317 2011-01-23 0.814979 2011-01-24 0.668641 2011-01-25 0.522303 2011-01-26 0.507709 2011-01-27 0.493115 2011-01-28 0.478521 2011-01-29 0.353632 2011-01-30 0.228744 ... 2011-02-28 0.258060 2011-03-01 -0.207988 2011-03-02 -0.674035 2011-03-03 -0.457174 2011-03-04 -0.240313 2011-03-05 -0.023452 2011-03-06 0.126218 2011-03-07 0.275887 2011-03-08 0.425557 2011-03-09 -0.031310 2011-03-10 -0.488177 2011-03-11 -0.945044 2011-03-12 -0.783820 2011-03-13 -0.622595 2011-03-14 -0.461371 2011-03-15 -0.138962 2011-03-16 0.183446 2011-03-17 0.505855 2011-03-18 0.276080 2011-03-19 0.046306 2011-03-20 -0.183469 2011-03-21 -0.036376 2011-03-22 0.110717 2011-03-23 0.257810 2011-03-24 0.421242 2011-03-25 0.584674 2011-03-26 0.748106 2011-03-27 0.826636 2011-03-28 0.905165 2011-03-29 0.983694 Freq: D, Length: 88, dtype: float64
Pandas滑动窗口:
滑动窗口就是能够根据指定的单位长度来框住时间序列,从而计算框内的统计指标。相当于一个长度指定的滑块在刻度尺上面滑动,每滑动一个单位即可反馈滑块内的数据。
滑动窗口可以使数据更加平稳,浮动范围会比较小,具有代表性,单独拿出一个数据可能或多或少会离群,有差异或者错误,使用滑动窗口会更规范一些。
%matplotlib inline import matplotlib.pylab import numpy as np import pandas as pd df = pd.Series(np.random.randn(600), index = pd.date_range(\'7/1/2016\', freq = \'D\', periods = 600)) df.head() 结果: 2016-07-01 -0.192140 2016-07-02 0.357953 2016-07-03 -0.201847 2016-07-04 -0.372230 2016-07-05 1.414753 Freq: D, dtype: float64 r = df.rolling(window = 10) r#Rolling [window=10,center=False,axis=0] #r.max, r.median, r.std, r.skew倾斜度, r.sum, r.var print(r.mean()) 结果: 2016-07-01 NaN 2016-07-02 NaN 2016-07-03 NaN 2016-07-04 NaN 2016-07-05 NaN 2016-07-06 NaN 2016-07-07 NaN 2016-07-08 NaN 2016-07-09 NaN 2016-07-10 0.300133 2016-07-11 0.284780 2016-07-12 0.252831 2016-07-13 0.220699 2016-07-14 0.167137 2016-07-15 0.018593 2016-07-16 -0.061414 2016-07-17 -0.134593 2016-07-18 -0.153333 2016-07-19 -0.218928 2016-07-20 -0.169426 2016-07-21 -0.219747 2016-07-22 -0.181266 2016-07-23 -0.173674 2016-07-24 -0.130629 2016-07-25 -0.166730 2016-07-26 -0.233044 2016-07-27 -0.256642 2016-07-28 -0.280738 2016-07-29 -0.289893 2016-07-30 -0.379625 ... 2018-01-22 -0.211467 2018-01-23 0.034996 2018-01-24 -0.105910 2018-01-25 -0.145774 2018-01-26 -0.089320 2018-01-27 -0.164370 2018-01-28 -0.110892 2018-01-29 -0.205786 2018-01-30 -0.101162 2018-01-31 -0.034760 2018-02-01 0.229333 2018-02-02 0.043741 2018-02-03 0.052837 2018-02-04 0.057746 2018-02-05 -0.071401 2018-02-06 -0.011153 2018-02-07 -0.045737 2018-02-08 -0.021983 2018-02-09 -0.196715 2018-02-10 -0.063721 2018-02-11 -0.289452 2018-02-12 -0.050946 2018-02-13 -0.047014 2018-02-14 0.048754 2018-02-15 0.143949 2018-02-16 0.424823 2018-02-17 0.361878 2018-02-18 0.363235 2018-02-19 0.517436 2018-02-20 0.368020 Freq: D, Length: 600, dtype: float64 import matplotlib.pyplot as plt %matplotlib inline plt.figure(figsize=(15, 5)) df.plot(style=\'r--\') df.rolling(window=10).mean().plot(style=\'b\')#<matplotlib.axes._subplots.AxesSubplot at 0x249627fb6d8>
结果:
数据平稳性与差分法:
基本模型:自回归移动平均模型(ARMA(p,q))是时间序列中最为重要的模型之一。它主要由两部分组成: AR代表p阶自回归过程,MA代表q阶移动平均过程。
平稳性检验
我们知道序列平稳性是进行时间序列分析的前提条件,很多人都会有疑问,为什么要满足平稳性的要求呢?在大数定理和中心定理中要求样本同分布(这里同分布等价于时间序列中的平稳性),而我们的建模过程中有很多都是建立在大数定理和中心极限定理的前提条件下的,如果它不满足,得到的许多结论都是不可靠的。以虚假回归为例,当响应变量和输入变量都平稳时,我们用t统计量检验标准化系数的显著性。而当响应变量和输入变量不平稳时,其标准化系数不在满足t分布,这时再用t检验来进行显著性分析,导致拒绝原假设的概率增加,即容易犯第一类错误,从而得出错误的结论。
平稳时间序列有两种定义:严平稳和宽平稳
严平稳顾名思义,是一种条件非常苛刻的平稳性,它要求序列随着时间的推移,其统计性质保持不变。对于任意的τ,其联合概率密度函数满足:
严平稳的条件只是理论上的存在,现实中用得比较多的是宽平稳的条件。
宽平稳也叫弱平稳或者二阶平稳(均值和方差平稳),它应满足:
- 常数均值
- 常数方差
- 常数自协方差
ARIMA 模型对时间序列的要求是平稳型。因此,当你得到一个非平稳的时间序列时,首先要做的即是做时间序列的差分,直到得到一个平稳时间序列。如果你对时间序列做d次差分才能得到一个平稳序列,那么可以使用ARIMA(p,d,q)模型,其中d是差分次数。
二阶差分是指在一阶差分基础上再做一阶差分。
%load_ext autoreload %autoreload 2 %matplotlib inline %config InlineBackend.figure_format=\'retina\' from __future__ import absolute_import, division, print_function # http://www.lfd.uci.edu/~gohlke/pythonlibs/#xgboost各种python库文件的下载,基本可以找到所有的 import sys import os import pandas as pd import numpy as np # # Remote Data Access # import pandas_datareader.data as web # import datetime # # reference: https://pandas-datareader.readthedocs.io/en/latest/remote_data.html # TSA from Statsmodels import statsmodels.api as sm import statsmodels.formula.api as smf import statsmodels.tsa.api as smt # Display and Plotting import matplotlib.pylab as plt import seaborn as sns pd.set_option(\'display.float_format\', lambda x: \'%.5f\' % x) # pandas np.set_printoptions(precision=5, suppress=True) # numpy pd.set_option(\'display.max_columns\', 100) pd.set_option(\'display.max_rows\', 100) # seaborn plotting style sns.set(style=\'ticks\', context=\'poster\') 结果: The autoreload extension is already loaded. To reload it, use: %reload_ext autoreload
#Read the data #美国消费者信心指数 Sentiment = \'data/sentiment.csv\' Sentiment = pd.read_csv(Sentiment, index_col=0, parse_dates=[0])
Sentiment.head()
结果:
UMCSENT | |
---|---|
DATE | |
2000-01-01 | 112.00000 |
2000-02-01 | 111.30000 |
2000-03-01 | 107.10000 |
2000-04-01 | 109.20000 |
2000-05-01 | 110.70000 |
# Select the series from 2005 - 2016 sentiment_short = Sentiment.loc[\'2005\':\'2016\']
sentiment_short.plot(figsize=(12,8)) plt.legend(bbox_to_anchor=(1.25, 0.5)) plt.title("Consumer Sentiment") sns.despine()
结果:
sentiment_short[\'diff_1\'] = sentiment_short[\'UMCSENT\'].diff(1)#求差分值,一阶差分。 1指的是1个时间间隔,可更改。 sentiment_short[\'diff_2\'] = sentiment_short[\'diff_1\'].diff(1)#再求差分,二阶差分。 sentiment_short.plot(subplots=True, figsize=(18, 12))
结果:
array([<matplotlib.axes._subplots.AxesSubplot object at 0x000001D9383BACF8>, <matplotlib.axes._subplots.AxesSubplot object at 0x000001D939FAB6A0>, <matplotlib.axes._subplots.AxesSubplot object at 0x000001D93A139B70>], dtype=object)
ARIMA模型:
相关函数评估方法:
通过ACF和PACF的图选择出p值和q值。
建立ARIMA模型:
del sentiment_short[\'diff_2\'] del sentiment_short[\'diff_1\'] sentiment_short.head() print (type(sentiment_short))#<class \'pandas.core.frame.DataFrame\'>
fig = plt.figure(figsize=(12,8)) #acf ax1 = fig.add_subplot(211) fig = sm.graphics.tsa.plot_acf(sentiment_short, lags=20,ax=ax1) ax1.xaxis.set_ticks_position(\'bottom\') fig.tight_layout(); #pacf ax2 = fig.add_subplot(212) fig = sm.graphics.tsa.plot_pacf(sentiment_short, lags=20, ax=ax2) ax2.xaxis.set_ticks_position(\'bottom\') fig.tight_layout(); #下图中的阴影表示置信区间,可以看出不同阶数自相关性的变化情况,从而选出p值和q值
结果:
# 散点图也可以表示 lags=9 ncols=3 nrows=int(np.ceil(lags/ncols)) fig, axes = plt.subplots(ncols=ncols, nrows=nrows, figsize=(4*ncols, 4*nrows)) for ax, lag in zip(axes.flat, np.arange(1,lags+1, 1)): lag_str = \'t-{}\'.format(lag) X = (pd.concat([sentiment_short, sentiment_short.shift(-lag)], axis=1, keys=[\'y\'] + [lag_str]).dropna()) X.plot(ax=ax, kind=\'scatter\', y=\'y\', x=lag_str); corr = X.corr().as_matrix()[0][1] ax.set_ylabel(\'Original\') ax.set_title(\'Lag: {} (corr={:.2f})\'.format(lag_str, corr)); ax.set_aspect(\'equal\'); sns.despine(); fig.tight_layout();
结果:
# 更直观一些 #模板,使用时直接改自己的数据就行,用以下四个图进行评估和分析就可以 def tsplot(y, lags=None, title=\'\', figsize=(14, 8)): fig = plt.figure(figsize=figsize) layout = (2, 2) ts_ax = plt.subplot2grid(layout, (0, 0)) hist_ax = plt.subplot2grid(layout, (0, 1)) acf_ax = plt.subplot2grid(layout, (1, 0)) pacf_ax = plt.subplot2grid(layout, (1, 1)) y.plot(ax=ts_ax) ts_ax.set_title(title) y.plot(ax=hist_ax, kind=\'hist\', bins=25) hist_ax.set_title(\'Histogram\') smt.graphics.plot_acf(y, lags=lags, ax=acf_ax) smt.graphics.plot_pacf(y, lags=lags, ax=pacf_ax) [ax.set_xlim(0) for ax in [acf_ax, pacf_ax]] sns.despine() plt.tight_layout() return ts_ax, acf_ax, pacf_ax tsplot(sentiment_short, title=\'Consumer Sentiment\', lags=36);
结果:
参数选择:
BIC的结果受样本的影响,使用同一样本时,可以选择BIC。
%load_ext autoreload %autoreload 2 %matplotlib inline %config InlineBackend.figure_format=\'retina\' from __future__ import absolute_import, division, print_function import sys import os import pandas as pd import numpy as np # TSA from Statsmodels import statsmodels.api as sm import statsmodels.formula.api as smf import statsmodels.tsa.api as smt # Display and Plotting import matplotlib.pylab as plt import seaborn as sns pd.set_option(\'display.float_format\', lambda x: \'%.5f\' % x) # pandas np.set_printoptions(precision=5, suppress=True) # numpy pd.set_option(\'display.max_columns\', 100) pd.set_option(\'display.max_rows\', 100) # seaborn plotting style sns.set(style=\'ticks\', context=\'poster\')
filename_ts = \'data/series1.csv\' ts_df = pd.read_csv(filename_ts, index_col=0, parse_dates=[0]) n_sample = ts_df.shape[0]
print(ts_df.shape) print(ts_df.head()) 结果: (120, 1) value 2006-06-01 0.21507 2006-07-01 1.14225 2006-08-01 0.08077 2006-09-01 -0.73952 2006-10-01 0.53552
# Create a training sample and testing sample before analyzing the series n_train=int(0.95*n_sample)+1 n_forecast=n_sample-n_train #ts_df ts_train = ts_df.iloc[:n_train][\'value\'] ts_test = ts_df.iloc[n_train:][\'value\'] print(ts_train.shape) print(ts_test.shape) print("Training Series:", "\\n", ts_train.tail(), "\\n") print("Testing Series:", "\\n", ts_test.head())
结果:
(115,) (5,) Training Series: 2015-08-01 0.60371 2015-09-01 -1.27372 2015-10-01 -0.93284 2015-11-01 0.08552 2015-12-01 1.20534 Name: value, dtype: float64 Testing Series: 2016-01-01 2.16411 2016-02-01 0.95226 2016-03-01 0.36485 2016-04-01 -2.26487 2016-05-01 -2.38168 Name: value, dtype: float64
def tsplot(y, lags=None, title=\'\', figsize=(14, 8)): fig = plt.figure(figsize=figsize) layout = (2, 2) ts_ax = plt.subplot2grid(layout, (0, 0)) hist_ax = plt.subplot2grid(layout, (0, 1)) acf_ax = plt.subplot2grid(layout, (1, 0)) pacf_ax = plt.subplot2grid(layout, (1, 1)) y.plot(ax=ts_ax) ts_ax.set_title(title) y.plot(ax=hist_ax, kind=\'hist\', bins=25) hist_ax.set_title(\'Histogram\') smt.graphics.plot_acf(y, lags=lags, ax=acf_ax) smt.graphics.plot_pacf(y, lags=lags, ax=pacf_ax) [ax.set_xlim(0) for ax in [acf_ax, pacf_ax]] sns.despine() fig.tight_layout() return ts_ax, acf_ax, pacf_ax
tsplot(ts_train, title=\'A Given Training Series\', lags=20);
结果:
#Model Estimation # Fit the model arima200 = sm.tsa.SARIMAX(ts_train, order=(2,0,0))#order里边的三个参数p,d,q model_results = arima200.fit()#fit模型
import itertools #当多组值都不符合时,遍历多组值,得出最好的值 p_min = 0 d_min = 0 q_min = 0 p_max = 4 d_max = 0 q_max = 4 # Initialize a DataFrame to store the results results_bic = pd.DataFrame(index=[\'AR{}\'.format(i) for i in range(p_min,p_max+1)], columns=[\'MA{}\'.format(i) for i in range(q_min,q_max+1)]) for p,d,q in itertools.product(range(p_min,p_max+1), range(d_min,d_max+1), range(q_min,q_max+1)): if p==0 and d==0 and q==0: results_bic.loc[\'AR{}\'.format(p), \'MA{}\'.format(q)] = np.nan continue try: model = sm.tsa.SARIMAX(ts_train, order=(p, d, q), #enforce_stationarity=False, #enforce_invertibility=False, ) results = model.fit() results_bic.loc[\'AR{}\'.format(p), \'MA{}\'.format(q)] = results.bic except: continue results_bic = results_bic[results_bic.columns].astype(float)
fig, ax = plt.subplots(figsize=(10, 8)) ax = sns.heatmap(results_bic, mask=results_bic.isnull(), ax=ax, annot=True, fmt=\'.2f\', ); ax.set_title(\'BIC\');
结果:
# Alternative model selection method, limited to only searching AR and MA parameters train_results = sm.tsa.arma_order_select_ic(ts_train, ic=[\'aic\', \'bic\'], trend=\'nc\', max_ar=4, max_ma=4) print(\'AIC\', train_results.aic_min_order) print(\'BIC\', train_results.bic_min_order) 结果:得出两个不同的标准,比较尴尬,还需要进行筛选 AIC (4, 2) BIC (1, 1)
#残差分析 正态分布 QQ图线性 model_results.plot_diagnostics(figsize=(16, 12));#statsmodels库
结果:
Q-Q图:越像直线,则是正态分布;越不是直线,离正态分布越远。
时间序列建模基本步骤:
- 获取被观测系统时间序列数据;
- 对数据绘图,观测是否为平稳时间序列;对于非平稳时间序列要先进行d阶差分运算,化为平稳时间序列;
- 经过第二步处理,已经得到平稳时间序列。要对平稳时间序列分别求得其自相关系数ACF 和偏自相关系数PACF ,通过对自相关图和偏自相关图的分析,得到最佳的阶层 p 和阶数 q
- 由以上得到的 ,得到ARIMA模型。然后开始对得到的模型进行模型检验。
股票预测(属于回归):
%matplotlib inline import pandas as pd import pandas_datareader#用于从雅虎财经获取股票数据 import datetime import matplotlib.pylab as plt import seaborn as sns from matplotlib.pylab import style from statsmodels.tsa.arima_model import ARIMA from statsmodels.graphics.tsaplots import plot_acf, plot_pacf style.use(\'ggplot\') plt.rcParams[\'font.sans-serif\'] = [\'SimHei\'] plt.rcParams[\'axes.unicode_minus\'] = False
stockFile = \'data/T10yr.csv\' stock = pd.read_csv(stockFile, index_col=0, parse_dates=[0])#将索引index设置为时间,parse_dates对日期格式处理为标准格式。 stock.head(10)
结果:
Open | High | Low | Close | Volume | Adj Close | |
---|---|---|---|---|---|---|
Date | ||||||
2000-01-03 | 6.498 | 6.603 | 6.498 | 6.548 | 0 | 6.548 |
2000-01-04 | 6.530 | 6.548 | 6.485 | 6.485 | 0 | 6.485 |
2000-01-05 | 6.521 | 6.599 | 6.508 | 6.599 | 0 | 6.599 |
2000-01-06 | 6.558 | 6.585 | 6.540 | 6.549 | 0 | 6.549 |
2000-01-07 | 6.545 | 6.595 | 6.504 | 6.504 | 0 | 6.504 |
2000-01-10 | 6.540 | 6.567 | 6.536 | 6.558 | 0 | 6.558 |
2000-01-11 | 6.600 | 6.664 | 6.595 | 6.664 | 0 | 6.664 |
2000-01-12 | 6.659 | 6.696 | 6.645 | 6.696 | 0 | 6.696 |
2000-01-13 | 6.664 | 6.705 | 6.618 | 6.618 | 0 | 6.618 |
2000-01-14 | 6.623 | 6.688 | 6.563 | 6.674 | 0 | 6.674 |
stock_week = stock[\'Close\'].resample(\'W-MON\').mean() stock_train = stock_week[\'2000\':\'2015\']
stock_train.plot(figsize=(12,8)) plt.legend(bbox_to_anchor=(1.25, 0.5)) plt.title("Stock Close") sns.despine()
结果:
stock_diff = stock_train.diff() stock_diff = stock_diff.dropna() plt.figure() plt.plot(stock_diff) plt.title(\'一阶差分\') plt.show()
结果:
acf = plot_acf(stock_diff, lags=20) plt.title("ACF") acf.show()
结果:
pacf = plot_pacf(stock_diff, lags=20) plt.title("PACF") pacf.show()
结果:
model = ARIMA(stock_train, order=(1, 1, 1),freq=\'W-MON\')
result = model.fit() #print(result.summary())#统计出ARIMA模型的指标
pred = result.predict(\'20140609\', \'20160701\',dynamic=True, typ=\'levels\')#预测,指定起始与终止时间。预测值起始时间必须在原始数据中,终止时间不需要 print (pred) 结果: 2014-06-09 2.463559 2014-06-16 2.455539 2014-06-23 2.449569 2014-06-30 2.444183 2014-07-07 2.438962 2014-07-14 2.433788 2014-07-21 2.428627 2014-07-28 2.423470 2014-08-04 2.418315 2014-08-11 2.413159 2014-08-18 2.408004 2014-08-25 2.402849 2014-09-01 2.397693 2014-09-08 2.392538 2014-09-15 2.387383 2014-09-22 2.382227 2014-09-29 2.377072 2014-10-06 2.371917 2014-10-13 2.366761 2014-10-20 2.361606 2014-10-27 2.356451 2014-11-03 2.351296 2014-11-10 2.346140 2014-11-17 2.340985 2014-11-24 2.335830 2014-12-01 2.330674 2014-12-08 2.325519 2014-12-15 2.320364 2014-12-22 2.315208 2014-12-29 2.310053 ... 2015-12-07 2.057443 2015-12-14 2.052288 2015-12-21 2.047132 2015-12-28 2.041977 2016-01-04 2.036822 2016-01-11 2.031666 2016-01-18 2.026511 2016-01-25 2.021356 2016-02-01 2.016200 2016-02-08 2.011045 2016-02-15 2.005890 2016-02-22 2.000735 2016-02-29 1.995579 2016-03-07 1.990424 2016-03-14 1.985269 2016-03-21 1.980113 2016-03-28 1.974958 2016-04-04 1.969803 2016-04-11 1.964647 2016-04-18 1.959492 2016-04-25 1.954337 2016-05-02 1.949181 2016-05-09 1.944026 2016-05-16 1.938871 2016-05-23 1.933716 2016-05-30 1.928560 2016-06-06 1.923405 2016-06-13 1.918250 2016-06-20 1.913094 2016-06-27 1.907939 Freq: W-MON, Length: 108, dtype: float64
plt.figure(figsize=(6, 6)) plt.xticks(rotation=45) plt.plot(pred) plt.plot(stock_train)#[<matplotlib.lines.Line2D at 0x28025665278>]
结果:
使用tfresh库进行分类任务:
tsfresh是开源的提取时序数据特征的python包,能够提取出超过64种特征,堪称提取时序特征的瑞士军刀。用到时tfresh查官方文档
%matplotlib inline import matplotlib.pylab as plt import seaborn as sns from tsfresh.examples.robot_execution_failures import download_robot_execution_failures, load_robot_execution_failures from tsfresh import extract_features, extract_relevant_features, select_features from tsfresh.utilities.dataframe_functions import impute from tsfresh.feature_extraction import ComprehensiveFCParameters from sklearn.tree import DecisionTreeClassifier from sklearn.cross_validation import train_test_split from sklearn.metrics import classification_report #http://tsfresh.readthedocs.io/en/latest/text/quick_start.html#官方文档
download_robot_execution_failures() df, y = load_robot_execution_failures() df.head()
结果:
id time a b c d e f 0 1 0 -1 -1 63 -3 -1 0 1 1 1 0 0 62 -3 -1 0 2 1 2 -1 -1 61 -3 0 0 3 1 3 -1 -1 63 -2 -1 0 4 1 4 -1 -1 63 -3 -1 0
df[df.id == 3][[\'time\', \'a\', \'b\', \'c\', \'d\', \'e\', \'f\']].plot(x=\'time\', title=\'Success example (id 3)\', figsize=(12, 6)); df[df.id == 20][[\'time\', \'a\', \'b\', \'c\', \'d\', \'e\', \'f\']].plot(x=\'time\', title=\'Failure example (id 20)\', figsize=(12, 6));
结果:
extraction_settings = ComprehensiveFCParameters()#提取特征
#column_id (str) – The name of the id column to group by #column_sort (str) – The name of the sort column. X = extract_features(df, column_id=\'id\', column_sort=\'time\',#以id为聚合,以time排序 default_fc_parameters=extraction_settings, impute_function= impute)
X.head()#提取到的特征
结果:
a__mean_abs_change_quantiles__qh_1.0__ql_0.8 a__percentage_of_reoccurring_values_to_all_values a__mean_abs_change_quantiles__qh_1.0__ql_0.2 a__mean_abs_change_quantiles__qh_1.0__ql_0.0 a__large_standard_deviation__r_0.45 a__absolute_sum_of_changes a__mean_abs_change_quantiles__qh_1.0__ql_0.4 a__mean_second_derivate_central a__autocorrelation__lag_4 a__binned_entropy__max_bins_10 ... f__fft_coefficient__coeff_0 f__fft_coefficient__coeff_1 f__fft_coefficient__coeff_2 f__fft_coefficient__coeff_3 f__fft_coefficient__coeff_4 f__fft_coefficient__coeff_5 f__fft_coefficient__coeff_6 f__fft_coefficient__coeff_7 f__fft_coefficient__coeff_8 f__fft_coefficient__coeff_9 id 1 0.142857 0.933333 0.142857 0.142857 0.0 2.0 0.142857 -0.038462 0.17553 0.244930 ... 0.0 0.000000 0.000000 0.000000 0.000000 0.0 0.000000 0.000000 0.0 0.0 2 0.000000 1.000000 0.400000 1.000000 0.0 14.0 0.400000 -0.038462 0.17553 0.990835 ... -4.0 0.744415 1.273659 -0.809017 1.373619 0.5 0.309017 -1.391693 0.0 0.0 3 0.000000 0.933333 0.714286 0.714286 0.0 10.0 0.714286 -0.038462 0.17553 0.729871 ... -4.0 -0.424716 0.878188 1.000000 1.851767 0.5 1.000000 -2.805239 0.0 0.0 4 0.000000 1.000000 0.800000 1.214286 0.0 17.0 0.800000 -0.038462 0.17553 1.322950 ... -5.0 -1.078108 3.678858 -3.618034 -1.466977 -0.5 -1.381966 -0.633773 0.0 0.0 5 2.000000 0.866667 0.916667 0.928571 0.0 13.0 0.916667 0.038462 0.17553 1.020037 ... -2.0 -3.743460 3.049653 -0.618034 1.198375 -0.5 1.618034 -0.004568 0.0 0.0 5 rows × 1332 columns
X.info() #结果: <class \'pandas.core.frame.DataFrame\'> Int64Index: 88 entries, 1 to 88 Columns: 1332 entries, a__mean_abs_change_quantiles__qh_1.0__ql_0.8 to f__fft_coefficient__coeff_9 dtypes: float64(1332) memory usage: 916.4 KB
X_filtered = extract_relevant_features(df, y, column_id=\'id\', column_sort=\'time\', default_fc_parameters=extraction_settings)#特征过滤,选择最相关的特征。具体了解查看官方文档
X_filtered.head()#新特征
结果:
a__abs_energy a__range_count__max_1__min_-1 b__abs_energy e__variance e__standard_deviation e__abs_energy c__standard_deviation c__variance a__standard_deviation a__variance ... b__has_duplicate_max b__cwt_coefficients__widths_(2, 5, 10, 20)__coeff_14__w_5 b__cwt_coefficients__widths_(2, 5, 10, 20)__coeff_13__w_2 e__quantile__q_0.1 a__ar_coefficient__k_10__coeff_1 a__quantile__q_0.2 b__quantile__q_0.7 f__large_standard_deviation__r_0.35 f__quantile__q_0.9 d__spkt_welch_density__coeff_5 id 1 14.0 15.0 13.0 0.222222 0.471405 10.0 1.203698 1.448889 0.249444 0.062222 ... 1.0 -0.751682 -0.310265 -1.0 0.125000 -1.0 -1.0 0.0 0.0 0.037795 2 25.0 13.0 76.0 4.222222 2.054805 90.0 4.333846 18.782222 0.956847 0.915556 ... 1.0 0.057818 -0.202951 -3.6 -0.078829 -1.0 -1.0 1.0 0.0 0.319311 3 12.0 14.0 40.0 3.128889 1.768867 103.0 4.616877 21.315556 0.596285 0.355556 ... 0.0 0.912474 0.539121 -4.0 0.084836 -1.0 0.0 1.0 0.0 9.102780 4 16.0 10.0 60.0 7.128889 2.669998 124.0 3.833188 14.693333 0.952190 0.906667 ... 0.0 -0.609735 -2.641390 -4.6 0.003108 -1.0 1.0 0.0 0.0 56.910262 5 17.0 13.0 46.0 4.160000 2.039608 180.0 4.841487 23.440000 0.879394 0.773333 ... 0.0 0.072771 0.591927 -5.0 0.087906 -1.0 0.8 0.0 0.6 22.841805 5 rows × 300 columns
X_filtered.info()
结果:
<class \'pandas.core.frame.DataFrame\'> Int64Index: 88 entries, 1 to 88 Columns: 300 entries, a__abs_energy to d__spkt_welch_density__coeff_5 dtypes: float64(300) memory usage: 206.9 KB
X_train, X_test, X_filtered_train, X_filtered_test, y_train, y_test = train_test_split(X, X_filtered, y, test_size=.4)
cl = DecisionTreeClassifier() cl.fit(X_train, y_train) print(classification_report(y_test, cl.predict(X_test)))#对模型进行评估,可以看出这个结果还不错
结果:
precision recall f1-score support 0 1.00 0.89 0.94 9 1 0.96 1.00 0.98 27 avg / total 0.97 0.97 0.97 36
cl.n_features_#1332
cl2 = DecisionTreeClassifier() cl2.fit(X_filtered_train, y_train) print(classification_report(y_test, cl2.predict(X_filtered_test)))
结果:
cl2 = DecisionTreeClassifier() cl2.fit(X_filtered_train, y_train) print(classification_report(y_test, cl2.predict(X_filtered_test))) cl2 = DecisionTreeClassifier() cl2.fit(X_filtered_train, y_train) print(classification_report(y_test, cl2.predict(X_filtered_test))) precision recall f1-score support 0 1.00 0.78 0.88 9 1 0.93 1.00 0.96 27 avg / total 0.95 0.94 0.94 36
cl2.n_features_#300
维基百科词条EDA
探索性数据分析(EDA)目的是最大化对数据的直觉,完成这个事情的方法只能是结合统计学的图形以各种形式展现出来。通过EDA可以实现:
1. 得到数据的直观表现
2. 发现潜在的结构
3. 提取重要的变量
4. 处理异常值
5. 检验统计假设
6. 建立初步模型
7. 决定最优因子的设置
import pandas as pd import numpy as np import matplotlib.pyplot as plt import re %matplotlib inline
train = pd.read_csv(\'train_1.csv\').fillna(0) train.head()
结果:
Page 2015-07-01 2015-07-02 2015-07-03 2015-07-04 2015-07-05 2015-07-06 2015-07-07 2015-07-08 2015-07-09 ... 2016-12-22 2016-12-23 2016-12-24 2016-12-25 2016-12-26 2016-12-27 2016-12-28 2016-12-29 2016-12-30 2016-12-31
0 2NE1_zh.wikipedia.org_all-access_spider 18.0 11.0 5.0 13.0 14.0 9.0 9.0 22.0 26.0 ... 32.0 63.0 15.0 26.0 14.0 20.0 22.0 19.0 18.0 20.0
1 2PM_zh.wikipedia.org_all-access_spider 11.0 14.0 15.0 18.0 11.0 13.0 22.0 11.0 10.0 ... 17.0 42.0 28.0 15.0 9.0 30.0 52.0 45.0 26.0 20.0
2 3C_zh.wikipedia.org_all-access_spider 1.0 0.0 1.0 1.0 0.0 4.0 0.0 3.0 4.0 ... 3.0 1.0 1.0 7.0 4.0 4.0 6.0 3.0 4.0 17.0
3 4minute_zh.wikipedia.org_all-access_spider 35.0 13.0 10.0 94.0 4.0 26.0 14.0 9.0 11.0 ... 32.0 10.0 26.0 27.0 16.0 11.0 17.0 19.0 10.0 11.0
4 52_Hz_I_Love_You_zh.wikipedia.org_all-access_s... 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 ... 48.0 9.0 25.0 13.0 3.0 11.0 27.0 13.0 36.0 10.0
5 rows × 551 columns
train.info() 结果:<class \'pandas.core.frame.DataFrame\'> RangeIndex: 145063 entries, 0 to 145062 Columns: 551 entries, Page to 2016-12-31 dtypes: float64(550), object(1) memory usage: 609.8+ MB
for col in train.columns[1:]: train[col] = pd.to_numeric(train[col],downcast=\'integer\')#float数据较为占内存,从上表可以看出,小数点后都是0,可将数据转换为int,减小内存。 train.head()
结果:
Page 2015-07-01 2015-07-02 2015-07-03 2015-07-04 2015-07-05 2015-07-06以上是关于Python时间序列分析的主要内容,如果未能解决你的问题,请参考以下文章
python分析apache和nginx日志文件输出访客ip列表的代码