python - 来自堆叠数据帧的 fill_between

Question

我有以下数据框:

symbol       DAL        MS       QQQ       SPY      TLT  XLE
symbol                                                      
DAL          NaN       NaN       NaN       NaN      NaN  NaN
MS      0.560979       NaN       NaN       NaN      NaN  NaN
QQQ     0.621045  0.789771       NaN       NaN      NaN  NaN
SPY    -0.576444 -0.843485 -0.953304       NaN      NaN  NaN
TLT     0.186840  0.421957  0.333320 -0.347808      NaN  NaN
XLE     0.115093  0.578970  0.559711 -0.701126  0.38047  NaN

然后我对数据帧进行堆叠和排序，并将结果绘制为条形图，如下所示:

dfstacked = corr_df.stack().order()
dfstacked.plot(kind='bar')

symbol  symbol
SPY     QQQ      -0.953304
        MS       -0.843485
XLE     SPY      -0.701126
SPY     DAL      -0.576444
TLT     SPY      -0.347808
XLE     DAL       0.115093
TLT     DAL       0.186840
        QQQ       0.333320
XLE     TLT       0.380470
TLT     MS        0.421957
XLE     QQQ       0.559711
MS      DAL       0.560979
XLE     MS        0.578970
QQQ     DAL       0.621045
        MS        0.789771

我现在想做的(没有成功)不是将其绘制为条形图，而是通过填充零以下和以上的区域来绘制它。我的猜测是我应该使用类似于以下示例的 fill_between:link :

ax.fill_between(dfstacked.index, 0, dfstacked.values, where = dfstacked.values > 0, interpolate=True)
ax.fill_between(dfstacked.index, dfstacked.values, 0, where = dfstacked.values < 0, interpolate=True)

我收到错误:TypeError: ufunc 'isfinite' 不支持输入类型，并且根据转换规则 ''safe'' 无法将输入安全地强制转换为任何受支持的类型

Answer 1

你试试reset_index :

dfstacked = dfstacked.reset_index(drop=True)
print dfstacked
0    -0.953304
1    -0.843485
2    -0.701126
3    -0.576444
4    -0.347808
5     0.115093
6     0.186840
7     0.333320
8     0.380470
9     0.421957
10    0.559711
11    0.560979
12    0.578970
13    0.621045
14    0.789771
dtype: float64

然后从multiindex设置axis x:

import matplotlib.pyplot as plt
import matplotlib.ticker as ticker


dfstacked = corr_df.stack().order()

ticklabels = dfstacked.index.tolist()

dfstacked = dfstacked.reset_index(drop=True)
print dfstacked


ax = dfstacked.plot()

ax.fill_between(dfstacked.index, 0, dfstacked.values, where = dfstacked.values > 0, interpolate=True)
ax.fill_between(dfstacked.index, dfstacked.values, 0, where = dfstacked.values < 0, interpolate=True)
ax.xaxis.set_major_formatter(ticker.FixedFormatter(ticklabels))
plt.xticks(rotation=90)    
plt.show()