1

I have two Series that are of the same length and datatype. Both are float64. The only difference are the indexes both are dates but one date is at the beginnning of the month and the other is at the end of the month. How can I do computations like correlation or covariance on Series or dataframes that have different indexes?

import numpy as np
from pandas import Series, DataFrame
import pandas as pd
import Quandl

IPO=Quandl.get("RITTER/US_IPO_STATS", authtoken="api key")
ir=Quandl.get("FRBC/REALRT", authtoken="api key")

ipo_splice=IPO[264:662]
new_ipo=ipo_splice['Gross Number of IPOs'];
new_ipo=new_ipo.T


ir_splice=ir[0:398]
new_ir=ir_splice['RR 1 Month']
new_ir=new_ir.T

new_ipo.corr(new_ir)
4

2 回答 2

0

reset_index(drop=True)对于你想要关联的东西，然后连接。

s1 = pd.DataFrame(np.random.rand(10), list('abcdefghij'), columns=['s1'])
s2 = pd.DataFrame(np.random.rand(10), list('ABCDEFGHIJ'), columns=['s2'])

print pd.concat([s.reset_index(drop=True) for s in [s1, s2]], axis=1).corr()


          s1        s2
s1  1.000000 -0.437945
s2 -0.437945  1.000000
于 2016-06-17T01:11:33.097 回答
0

您可以使用resample()函数来重新采样您的索引之一（我们的目标是同时拥有索引 BoM 或 EoM）：

数据：

In [63]: df_bom
Out[63]:
            val
2015-01-01   76
2015-02-01   27
2015-03-01   65
2015-04-01   71
2015-05-01    9
2015-06-01   23
2015-07-01   52
2015-08-01   10
2015-09-01   62
2015-10-01   25

In [64]: df_eom
Out[64]:
            val
2015-01-31   87
2015-02-28   16
2015-03-31   85
2015-04-30    4
2015-05-31   37
2015-06-30   63
2015-07-31    3
2015-08-31   73
2015-09-30   81
2015-10-31   69

解决方案：

In [61]: df_eom.resample('MS') + df_bom
C:\envs\py35\Scripts\ipython:1: FutureWarning: .resample() is now a deferred operation
use .resample(...).mean() instead of .resample(...)
Out[61]:
            val
2015-01-01  163
2015-02-01   43
2015-03-01  150
2015-04-01   75
2015-05-01   46
2015-06-01   86
2015-07-01   55
2015-08-01   83
2015-09-01  143
2015-10-01   94

In [62]: df_eom.resample('MS').join(df_bom, lsuffix='_lft')
C:\envs\py35\Scripts\ipython:1: FutureWarning: .resample() is now a deferred operation
use .resample(...).mean() instead of .resample(...)
Out[62]:
            val_lft  val
2015-01-01       87   76
2015-02-01       16   27
2015-03-01       85   65
2015-04-01        4   71
2015-05-01       37    9
2015-06-01       63   23
2015-07-01        3   52
2015-08-01       73   10
2015-09-01       81   62
2015-10-01       69   25

替代方法year- 通过和month部分合并 DF ：

In [69]: %paste
(pd.merge(df_bom, df_eom,
          left_on=[df_bom.index.year, df_bom.index.month],
          right_on=[df_eom.index.year, df_eom.index.month],
          suffixes=('_bom','_eom')))
## -- End pasted text --
Out[69]:
   key_0  key_1  val_bom  val_eom
0   2015      1       76       87
1   2015      2       27       16
2   2015      3       65       85
3   2015      4       71        4
4   2015      5        9       37
5   2015      6       23       63
6   2015      7       52        3
7   2015      8       10       73
8   2015      9       62       81
9   2015     10       25       69

设置：

In [59]: df_bom = pd.DataFrame({'val':np.random.randint(0,100, 10)}, index=pd.date_range('2015-01-01', periods=10, freq='MS'))

In [60]: df_eom = pd.DataFrame({'val':np.random.randint(0,100, 10)}, index=pd.date_range('2015-01-01', periods=10, freq='M'))
于 2016-06-17T08:09:55.083 回答