Python相关指数

Question

给定数据框“df”，我需要获取 Region =“California”的平均价格和总交易量之间的相关性指数。

给定数据框：

加州平均价格与总成交量之间的相关指数：

cali_mean = df.groupby('Region').get_group('California')['AveragePrice'].mean()
max_volume = (df.groupby('Region')['TotalVolume'].sum()).max() #Output: 1028981653.17

# Correlation index between California mean price and total volume
df[cali_mean].corr(df['max_volume'])

当我尝试确定加州平均价格与总成交量之间的相关指数时，我得到了以下错误消息。有办法解决这个问题吗？

错误消息

KeyError                                  Traceback (most recent call last)
~/opt/miniconda3/lib/python3.9/site-packages/pandas/core/indexes/base.py in get_loc(self, key, method, tolerance)
   3620             try:
-> 3621                 return self._engine.get_loc(casted_key)
   3622             except KeyError as err:

~/opt/miniconda3/lib/python3.9/site-packages/pandas/_libs/index.pyx in pandas._libs.index.IndexEngine.get_loc()

~/opt/miniconda3/lib/python3.9/site-packages/pandas/_libs/index.pyx in pandas._libs.index.IndexEngine.get_loc()

pandas/_libs/hashtable_class_helper.pxi in pandas._libs.hashtable.PyObjectHashTable.get_item()

pandas/_libs/hashtable_class_helper.pxi in pandas._libs.hashtable.PyObjectHashTable.get_item()

KeyError: 1.3939644970414187

The above exception was the direct cause of the following exception:

KeyError                                  Traceback (most recent call last)
/var/folders/wv/42dn23fd1cb0czpvqdnb6zw00000gn/T/ipykernel_18660/3247367876.py in <module>
      1 # Correlation index between California mean price and total volume
----> 2 df[cali_mean].corr(df['max_volume'])

~/opt/miniconda3/lib/python3.9/site-packages/pandas/core/frame.py in __getitem__(self, key)
   3503             if self.columns.nlevels > 1:
   3504                 return self._getitem_multilevel(key)
-> 3505             indexer = self.columns.get_loc(key)
   3506             if is_integer(indexer):
   3507                 indexer = [indexer]

~/opt/miniconda3/lib/python3.9/site-packages/pandas/core/indexes/base.py in get_loc(self, key, method, tolerance)
   3621                 return self._engine.get_loc(casted_key)
   3622             except KeyError as err:
-> 3623                 raise KeyError(key) from err
   3624             except TypeError:
   3625                 # If we have a listlike key, _check_indexing_error will raise

KeyError: 1.3939644970414187

Answer 1

请注意，相关性是两个向量的度量。所以你可以使用：

df = pd.read_csv('avocado.csv')
temp = df[df['Region']=='California']
temp['AveragePrice'].corr(temp['TotalVolume'])

输出：

-0.7913852550045145