X轴上的字符串值的堆叠直方图失败

debugcn 发表于 Dev

鸭嘴

我有以下堆积直方图的代码，当FIELD为数字时，它可以正常工作。然而，当我把FIELD_str那个，而不是1，2，3，...有abc1，abc2，abc3，等，那么它失败，出现错误TypeError: cannot concatenate 'str' and 'float' objects。如何用它们的字符串值替换（直接或间接）X轴中的数字（为了更好地读取图表，这是必需的）：

filter = df["CLUSTER"] == 1
plt.ylabel("Absolute frequency")
plt.hist([df["FIELD"][filter],df["FIELD"][~filter]],stacked=True,
          color=['#8A2BE2', '#EE3B3B'], label=['1','0'])
plt.legend()
plt.show()

数据集：

s_field1 = pd.Series(["5","5","5","8","8","9","10"]) 
s_field1_str = pd.Series(["abc1","abc1","abc1","abc2","abc2","abc3","abc4"]) 
s_cluster = pd.Series(["1","1","0","1","0","1","0"])  

df = pd.concat([s_field1, s_field1_str, s_cluster], axis=1)
df

编辑：

我试图创建字典，但无法弄清楚如何将其放在直方图中：

# since python 2.7
import collections
yes = collections.Counter(df["FIELD_str"][filter])
no = collections.Counter(df["FIELD_str"][~filter])

伊利亚·舒罗夫（Ilya V. Schurov）

您可能必须使用barplot而不是直方图，因为直方图的定义是针对数字（间隔）标度而不是名义（分类）标度的数据。您可以尝试以下方法：

import pandas as pd
import matplotlib.pyplot as plt
%matplotlib inline

s_field1 = pd.Series(["5","5","5","8","8","9","10"])
s_field1_str = pd.Series(["abc1","abc1","abc1","abc2","abc2","abc3","abc4"]) 
s_cluster = pd.Series(["1","1","0","1","0","1","0"])

df = pd.concat([s_field1, s_field1_str, s_cluster], axis=1)
df.columns = ['FIELD', 'FIELD_str', 'CLUSTER']
counts = df.groupby(['FIELD_str', 'CLUSTER']).count().unstack()
# calculate counts by CLUSTER and FIELD_str
counts.columns = counts.columns.get_level_values(1)
counts.index.name = 'xaxis label here'
ax = counts.plot.bar(stacked=True, title='Some title here')
ax.set_ylabel("yaxis label here")
plt.tight_layout()
plt.savefig("stacked_barplot.png")