python画箱线图采坑总结_箱线图为什么下面的线没有了

我现在是有5组数据，我想画成下图这种形式，因为我想给每一个图都指定一个上下边缘，然后不在这个范围内的数就画成异常值。在网上找资料找了很久，都没有找到方法，其实是我自己没搞懂箱线图的原理。

如下图所示，每一个箱线图都有上边缘，下边缘，箱体，异常值组成，箱体的上边是上四分位数，下边是下四分位数，中间是中位数
箱形图有5个参数：
下边缘（Q1），
下四分位数（Q2），又称“第一四分位数”，等于该样本中所有数值由小到大排列后第25%的数字；
中位数（Q3），又称“第二四分位数”等于该样本中所有数值由小到大排列后第50%的数字；
上四分位数（Q4），又称“第三四分位数”等于该样本中所有数值由小到大排列后第75%的数字；
上边缘（Q5），
异常值：超过上边缘或者下边缘的值
千万不要跟我一样以为上边缘是最大值，下边缘是最小值
上下边缘的确定是Q2-1.5IQR和Q4+1.5IQR，其中IQR=Q4-Q2;

下面我们来用程序验证一下

import numpy as np
import pandas as pd
import matplotlib.pyplot as plt
data={'neutral':[55,52,52,52,51,51,50,50,50,48,48,48,47,47,47,47,47,46,46,46,46,45,45,45,45,44,44,44,44,44,44,44,43,43,43,43,43,42,42,42,42,42,42,41,41,41,41,41,41,41,40,40,40,40,40,40,40,40,39,39,39,38,38,38,38,38,38,38,38,38,38,37,37,37,37,37,37,37,37,37,37,37,37,37,36,36,36,36,36,36,36,36,36,36,36,36,35,35,35,35,35,35,35,35,35,35,34,34,34,34,34,34,34,34,34,34,34,33,33,33,33,33,33,33,33,32,32,32,32,32,32,32,32,32,32,31,31,31,31,31,31,31,30,30,30,30,30,30,30,30,30,29,29,29,29,29,29,28,28,28,28,28,28,28,27,27,27,27,27,27,27,27,27,26,26,26,26,26,25,25,25,25,25,25,24,24,24,24,23,22,21,21,20,20,20,20,20,18,16,12]}
df = pd.DataFrame(data)
print(df.describe())
df.plot.box(title="Consumer spending in each country",whis=1.5)
plt.grid(linestyle="--", alpha=0.3)
plt.show()
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结果展示
我发现程序有一个异常点（这个异常点看坐标应该是12），而且上边缘是这个数列的最大值，下边缘不是这个数列的最小值，我们来计算一下
IQR=Q4-Q2=40.25-30=10.25
Q1=Q2-1.5IQR=30-1.5×10.25=14.625，那么下边缘应该是14.625,12超出了这个范围，所以被判为异常点

Q5=Q4+1.5IQR=40.25+15.375=55.625,这个数列所有的数都没有超过这个上边缘（最大只有55），所以上边没有异常点

现在我们改一下这个数列，再来看看结果

import numpy as np
import pandas as pd
import matplotlib.pyplot as plt
data={'neutral':[80,56,52,52,51,51,50,50,50,48,48,48,47,47,47,47,47,46,46,46,46,45,45,45,45,44,44,44,44,44,44,44,43,43,43,43,43,42,42,42,42,42,42,41,41,41,41,41,41,41,40,40,40,40,40,40,40,40,39,39,39,38,38,38,38,38,38,38,38,38,38,37,37,37,37,37,37,37,37,37,37,37,37,37,36,36,36,36,36,36,36,36,36,36,36,36,35,35,35,35,35,35,35,35,35,35,34,34,34,34,34,34,34,34,34,34,34,33,33,33,33,33,33,33,33,32,32,32,32,32,32,32,32,32,32,31,31,31,31,31,31,31,30,30,30,30,30,30,30,30,30,29,29,29,29,29,29,28,28,28,28,28,28,28,27,27,27,27,27,27,27,27,27,26,26,26,26,26,25,25,25,25,25,25,24,24,24,24,23,22,21,21,20,20,20,20,20,18,16,13]}
df = pd.DataFrame(data)
print(df.describe())
df.plot.box(title="Consumer spending in each country",whis=1.5)
plt.grid(linestyle="--", alpha=0.3)
plt.show()
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如下图，13不是异常点，80,56是异常点

但是，这个系数是可以改的，可以改成2.0试试

此时Q1=Q2-2IQR

Q5=Q4+2IQR

df.plot.box(title="Consumer spending in each country",whis=1.5)
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import numpy as np
import pandas as pd
import matplotlib.pyplot as plt
data={'neutral':[80,56,52,52,51,51,50,50,50,48,48,48,47,47,47,47,47,46,46,46,46,45,45,45,45,44,44,44,44,44,44,44,43,43,43,43,43,42,42,42,42,42,42,41,41,41,41,41,41,41,40,40,40,40,40,40,40,40,39,39,39,38,38,38,38,38,38,38,38,38,38,37,37,37,37,37,37,37,37,37,37,37,37,37,36,36,36,36,36,36,36,36,36,36,36,36,35,35,35,35,35,35,35,35,35,35,34,34,34,34,34,34,34,34,34,34,34,33,33,33,33,33,33,33,33,32,32,32,32,32,32,32,32,32,32,31,31,31,31,31,31,31,30,30,30,30,30,30,30,30,30,29,29,29,29,29,29,28,28,28,28,28,28,28,27,27,27,27,27,27,27,27,27,26,26,26,26,26,25,25,25,25,25,25,24,24,24,24,23,22,21,21,20,20,20,20,20,18,16,13]}
df = pd.DataFrame(data)
print(df.describe())
df.plot.box(title="Consumer spending in each country",whis=2.0)
plt.grid(linestyle="--", alpha=0.3)
plt.show()
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不知道可不可以上下限的倍数设的不一样啊
https://www.bilibili.com/video/BV1Jt4y1i76Q?from=search&seid=12376886745584686578
这个视频中说的，不是很懂它的意思，我也没试出来这之间的关系

df.plot.box(title="Consumer spending in each country",whis=(20,100))
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