pandas Python数据帧在微秒内重新采样
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Python Data Frame resample on micro second
提问by alphiii
I am working with resampling data frame and it works on hours, days mins, but doesn't resample less then sec. Program just hangs even on short time span. So am I missing something?
我正在使用重采样数据框，它可以在几小时、几天、几分钟内工作，但不会在不到 sec 的时间内重新采样。即使在很短的时间内，程序也会挂起。所以我错过了什么吗？
I tried 0.000001S, U etc... Nothing worked so far.
我尝试了 0.000001S、U 等......到目前为止没有任何效果。
my time format: 2015-08-29 19:30:47.015506
我的时间格式：2015-08-29 19:30:47.015506
you can see varable sf represent resampling freq.
你可以看到变量 sf 代表重采样频率。
grph = df.set_index('Date and Time').resample(sf, len).astype(int)
How can I resample data frame on micro seconds granularity?
如何以微秒粒度重新采样数据帧？
回答by YOBA
sf = "1U" #for one microsecond
For milliseconds/microseconds/seconds use:
对于毫秒/微秒/秒，请使用：
L milliseonds
U microseconds
S seconds
完整文档：
B business day frequency
C custom business day frequency (experimental)
D calendar day frequency
W weekly frequency
M month end frequency
BM business month end frequency
CBM custom business month end frequency
MS month start frequency
BMS business month start frequency
CBMS custom business month start frequency
Q quarter end frequency
BQ business quarter endfrequency
QS quarter start frequency
BQS business quarter start frequency
A year end frequency
BA business year end frequency
AS year start frequency
BAS business year start frequency
BH business hour frequency
H hourly frequency
T minutely frequency
S secondly frequency
L milliseonds
U microseconds
N nanoseconds
回答by Pilik
If I understand your problem correctly you can't resample microseconds to another frequency that is less than a second, right? I made a toy example and there doesn't seem to be a problem though:
如果我正确理解您的问题，您不能将微秒重新采样到另一个小于一秒的频率，对吗？我做了一个玩具示例，但似乎没有问题：
import pandas as pd
import numpy as np
np.random.seed(0)
index=pd.date_range('22/10/2010', periods=100000, freq='U')
example=pd.Series(index=index,data=np.random.randn(100000))
example.resample('ms',how='sum')
This gives the expected output.
这给出了预期的输出。
(I think your problem is that you are trying to resample data that are in a microsecond format to microseconds itself, which doesn't make any sense. You want to either upsample or downsample (as in my example).)
（我认为您的问题是您试图将微秒格式的数据重新采样为微秒本身，这没有任何意义。您想要上采样或下采样（如我的示例）。
