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<p>下面的代码片段从print部分显示
执行时没有问题:</p>
<pre><code>import pandas as pd
from matplotlib import pyplot as plt
import numpy as np
import csv
ts = pd.Series(np.random.randn(1000), index=pd.date_range('1/1/2000', periods=1000))
df = pd.DataFrame(np.random.randn(1000, 3), index=ts.index, columns=list('ABC'))
print (df)
print (df.index)
print (df.columns)
#df = df.cumsum() # this also is ok
df.plot()
plt.show()
A B C
2000-01-01 0.882544 -0.841398 1.745238
2000-01-02 1.798310 1.049662 -0.115292
2000-01-03 1.223243 -0.086322 -0.565204
2000-01-04 -0.587905 -0.609485 0.296248
2000-01-05 -1.603916 -0.397210 0.007550
2000-01-06 -0.821833 0.112760 -0.082558
...
...
2002-09-22 -0.530537 0.373358 2.920919
2002-09-23 0.121657 0.634864 -0.964255
2002-09-24 1.153799 2.468507 -2.087136
2002-09-25 -1.079853 0.684926 1.556522
2002-09-26 -2.163454 0.874373 1.942925
[1000 rows x 3 columns]
DatetimeIndex(['2000-01-01', '2000-01-02', '2000-01-03', '2000-01-04',
'2000-01-05', '2000-01-06', '2000-01-07', '2000-01-08',
'2000-01-09', '2000-01-10',
...
...
'2002-09-17', '2002-09-18', '2002-09-19', '2002-09-20',
'2002-09-21', '2002-09-22', '2002-09-23', '2002-09-24',
'2002-09-25', '2002-09-26'],
dtype='datetime64[ns]', length=1000, freq='D')
Index(['A', 'B', 'C'], dtype='object')
</code></pre>
<p>并生成一个很好的绘图(如预期的那样)<a href="https://i.stack.imgur.com/nes5V.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/nes5V.png" alt="enter image description here"/></a></p>
<p>但是,当我执行以下代码时</p>
<pre><code>import datetime
df = pd.read_csv(fullFileNameOutCSV, header=0, names=headerCSV,usecols=['SEK/EUR', 'SEK/DKK', 'SEK/NOK'])
pd.Timedelta(datetime.timedelta(days=1))
df.index = pd.date_range('2000-01-01',periods=4888)
df.index = pd.to_datetime(df.index)
print (df)
print (df.index)
print (df.columns)
df.plot()
plt.show()
SEK/EUR SEK/DKK SEK/NOK
2000-01-01 9.4696 7.4501 8.8550
2000-01-02 9.4025 7.4495 8.7745
2000-01-03 9.3050 7.4452 8.7335
2000-01-04 9.1800 7.4431 8.6295
2000-01-05 9.1650 7.4433 8.5900
2000-01-06 9.0985 7.4433 8.5585
...
...
2013-05-14 9.8188 7.4444 9.5858
2013-05-15 9.8005 7.4428 9.5655
2013-05-16 9.7823 7.4427 9.5548
2013-05-17 9.7825 7.4415 9.5628
2013-05-18 9.7645 7.4419 9.5620
2013-05-19 9.8030 7.4428 9.5705
[4888 rows x 3 columns]
DatetimeIndex(['2000-01-01', '2000-01-02', '2000-01-03', '2000-01-04',
'2000-01-05', '2000-01-06', '2000-01-07', '2000-01-08',
'2000-01-09', '2000-01-10',
...
...
'2013-05-10', '2013-05-11', '2013-05-12', '2013-05-13',
'2013-05-14', '2013-05-15', '2013-05-16', '2013-05-17',
'2013-05-18', '2013-05-19'],
dtype='datetime64[ns]', length=4888, freq='D')
</code></pre>
<p>情节不是我所期望的。
<a href="https://i.stack.imgur.com/Bi3it.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Bi3it.png" alt="enter image description here"/></a>
为了得到一个合理的绘图,我在这个代码段上尝试了许多不同的变体,但到目前为止,我还没有找到能够生成与第一个绘图类似的绘图的代码。注意,垂直轴刻度---是什么引起的?
为什么我不能得到一个类似于第一个代码片段的图呢?你知道吗</p>