每年与 pandas 的箱线图 [英] Yearly BoxPlots with Pandas
问题描述
我有一个DataFrame(每日多个时间序列),其中DateTimeIndex
作为index
,MultiIndex
作为columns
.我想选择一个列并创建一个箱形图,其中按年份对数据进行分组.我以为这很容易,但是我正在努力取得一些结果.
I have a DataFrame (multiple daily timeseries) with DateTimeIndex
as index
and MultiIndex
as columns
. I would like to select a column and create a Box Plot where data are grouped by year. I thought it was easy but I am struggling to get some result.
>>> daily.shape
(11319, 118)
>>> daily.index
DatetimeIndex(['1986-01-01', '1986-01-02', '1986-01-03', '1986-01-04',
'1986-01-05', '1986-01-06', '1986-01-07', '1986-01-08',
'1986-01-09', '1986-01-10',
...
'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'],
dtype='datetime64[ns]', name='timevalue', length=11319, freq=None)
>>> daily.columns
MultiIndex(levels=[['41B001', '41B004', '41B006', '41B008', '41B011', '41MEU1', '41N043', '41R001', '41R002', '41R012', '41WOL1', '41WOL2', '47E013', 'T1M001', 'T1M003'], ['BA-10.0', 'BA-2.5', 'BC', 'CO', 'CO2', 'NO', 'NO2', 'NOx', 'O3', 'PM-10.0', 'PM-2.5', 'RH', 'SO2', 'T', 'UVPM', 'VO-10.0', 'VO-2.5', 'WD', 'WS-s', 'WS-v', 'p']],
labels=[[0, 0, 0, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5, 5, 5, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 8, 8, 8, 8, 8, 8, 8, 8, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 11, 12, 12, 12, 12, 13, 13, 13, 13, 13, 13, 13, 14, 14, 14, 14, 14, 14, 14], [5, 6, 7, 3, 5, 6, 7, 8, 3, 5, 6, 7, 8, 3, 5, 6, 7, 12, 0, 1, 5, 6, 7, 8, 9, 10, 15, 16, 0, 1, 5, 6, 7, 9, 10, 15, 16, 0, 1, 2, 3, 5, 6, 7, 8, 9, 10, 12, 14, 15, 16, 0, 1, 2, 3, 5, 6, 7, 8, 9, 10, 12, 14, 15, 16, 2, 3, 4, 5, 6, 7, 12, 14, 0, 1, 2, 4, 5, 6, 7, 8, 9, 10, 12, 14, 15, 16, 0, 2, 3, 4, 5, 6, 7, 8, 9, 12, 14, 15, 4, 5, 6, 7, 12, 11, 13, 13, 17, 18, 19, 20, 11, 13, 13, 17, 18, 19, 20]],
names=['sitekey', 'measurandkey'])
我能做到的最好的是:
fig, axe = plt.subplots()
daily.loc[:,[('41R001', 'SO2')]].groupby(daily.index.map(lambda x: x.year)).boxplot(ax=axe, subplots=False, rot=90)
但是它需要其他后处理来标记轴.
But It will requires other postprocess for labelling axis.
当我尝试reset_index()
应用功能并使用pivot()
时,由于MultiIndex
,我出现了索引错误.
When I try to reset_index()
to apply function and using pivot()
, I have indexing error because of the MultiIndex
.
d = daily.reset_index()
d['timevalue']
例外是:无法处理非唯一的多索引!我不了解,因为在MultiIndex中没有出现TimeValue.我也尝试过.loc[]
,但我认为问题出在其他地方.
The Exception is: cannot handle a non-unique multi-index! That I do not understand since there is no occurrence of TimeValue in my MultiIndex. I also have tried .loc[]
but I think the problem is elsewhere.
所以,我要做的很简单:
So, what I would achieve is simple:
- 我有几年中的每日时间序列,并且这些时间序列是多索引的;
- 我想选择其中一个(使用
loc
和上面的示例中的复合键),并获得一个时间盒图,其中按年份对数据进行分组.
- I have daily timeseries among years and those timeseries are multi-indexed;
- I would like to select one of them (using
loc
and a composite key as in example above) and get a timeserie boxplot where data are grouped by year.
我认为这很容易,但是由于存在多个索引错误,因此我无法在此DataFrame中正确使用pivot()
.
I thought it could be easy, but I cannot properly use pivot()
with this DataFrame because of the mutli-index error.
推荐答案
如果您不介意使用seaborn
库,则可以很容易地绘制此图:
If you don't mind using seaborn
library you can make this plot pretty easily:
import pandas as pd
import seaborn as sns
index = pd.DatetimeIndex(start=pd.to_datetime('1985-01-01'),
end = pd.to_datetime('2017-03-08'),
freq='d')
df = pd.DataFrame(index = index,
data = np.random.uniform(-1,1,size=(index.shape[0],4)),
columns=pd.MultiIndex.from_arrays([['A','A','B','B'],
['d','e','d','e']]))
df['Year'] = df.index.year
# A B Year
# d e d e
# 1985-01-01 0.205208 -0.228484 0.296273 0.545031 1985
# 1985-01-02 0.546436 -0.538920 0.173388 0.848590 1985
# 1985-01-03 -0.367593 -0.974911 -0.796331 -0.946239 1985
# 1985-01-04 -0.346102 -0.951542 -0.975172 0.951099 1985
# 1985-01-05 0.973975 0.708254 -0.150454 0.145298 1985
ax = sns.boxplot(data = df, x='Year',y=('A','e'))
for item in ax.get_xticklabels():
item.set_rotation(90)
结果图像:
我尝试使用pandas.DataFrame.boxplot()
方法,但无法在短时间内(=)来解决此问题.
I tried using the pandas.DataFrame.boxplot()
method but couldn't make it work for this case in a short span of time =).
这篇关于每年与 pandas 的箱线图的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!