使用Mutual_info回归进行特征选择时重塑错误 [英] Reshape error when using mutual_info regression for feature selection
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问题描述
我正在尝试使用带有SelectKBest包装器的common_info_regression进行某些功能选择.但是，我一直遇到错误，指示我的功能列表需要重塑为2D数组，但不确定为什么我会不断收到此消息-
I am trying to do some feature selection using mutual_info_regression with SelectKBest wrapper. However I keep running into an error indicating that my list of features needs to be reshaped into a 2D array, not quite sure why I keep getting this message-
#feature selection before linear regression benchmark test
import sklearn
from sklearn.feature_selection import mutual_info_regression, SelectKBest
features = list(housing_data[housing_data.columns.difference(['sale_price'])])
target = 'sale_price'
new = SelectKBest(mutual_info_regression, k=20).fit_transform(features, target)
这是我的回溯:
---------------------------------------------------------------------------
ValueError Traceback (most recent call last)
<ipython-input-18-8c778124066c> in <module>()
3 features = list(housing_data[housing_data.columns.difference(['sale_price'])])
4 target = 'sale_price'
----> 5 new = SelectKBest(mutual_info_regression, k=20).fit_transform(features, target)
/usr/local/lib/python3.6/dist-packages/sklearn/base.py in fit_transform(self, X, y, **fit_params)
463 else:
464 # fit method of arity 2 (supervised transformation)
--> 465 return self.fit(X, y, **fit_params).transform(X)
466
467
/usr/local/lib/python3.6/dist-packages/sklearn/feature_selection/univariate_selection.py in fit(self, X, y)
339 self : object
340 """
--> 341 X, y = check_X_y(X, y, ['csr', 'csc'], multi_output=True)
342
343 if not callable(self.score_func):
/usr/local/lib/python3.6/dist-packages/sklearn/utils/validation.py in check_X_y(X, y, accept_sparse, accept_large_sparse, dtype, order, copy, force_all_finite, ensure_2d, allow_nd, multi_output, ensure_min_samples, ensure_min_features, y_numeric, warn_on_dtype, estimator)
754 ensure_min_features=ensure_min_features,
755 warn_on_dtype=warn_on_dtype,
--> 756 estimator=estimator)
757 if multi_output:
758 y = check_array(y, 'csr', force_all_finite=True, ensure_2d=False,
/usr/local/lib/python3.6/dist-packages/sklearn/utils/validation.py in check_array(array, accept_sparse, accept_large_sparse, dtype, order, copy, force_all_finite, ensure_2d, allow_nd, ensure_min_samples, ensure_min_features, warn_on_dtype, estimator)
550 "Reshape your data either using array.reshape(-1, 1) if "
551 "your data has a single feature or array.reshape(1, -1) "
--> 552 "if it contains a single sample.".format(array))
553
554 # in the future np.flexible dtypes will be handled like object dtypes
ValueError: Expected 2D array, got 1D array instead:
array=['APPBBL' 'APPDate' 'Address' 'AreaSource' 'AssessLand' 'AssessTot' 'BBL'
'BldgArea' 'BldgClass' 'BldgDepth' 'BldgFront' 'BoroCode' 'Borough'
'BsmtCode' 'BuiltFAR' 'CB2010' 'CD' 'CT2010' 'ComArea' 'CommFAR'
'CondoNo' 'Council' 'EDesigNum' 'Easements' 'ExemptLand' 'ExemptTot'
'Ext' 'FIRM07_FLA' 'FacilFAR' 'FactryArea' 'FireComp' 'GarageArea'
'HealthArea' 'HealthCent' 'HistDist' 'IrrLotCode' 'LandUse' 'Landmark'
'LotArea' 'LotDepth' 'LotFront' 'LotType' 'LtdHeight' 'MAPPLUTO_F'
'NumBldgs' 'NumFloors' 'OfficeArea' 'OtherArea' 'Overlay1' 'Overlay2'
'OwnerName' 'OwnerType' 'PFIRM15_FL' 'PLUTOMapID' 'PolicePrct' 'ProxCode'
'ResArea' 'ResidFAR' 'RetailArea' 'SHAPE_Area' 'SHAPE_Leng' 'SPDist1'
'SPDist2' 'SPDist3' 'Sanborn' 'SanitBoro' 'SanitDistr' 'SanitSub'
'SchoolDist' 'SplitZone' 'StrgeArea' 'TaxMap' 'Tract2010' 'UnitsRes'
'UnitsTotal' 'Unnamed: 0' 'Version' 'XCoord' 'YCoord' 'YearAlter1'
'YearAlter2' 'YearBuilt' 'ZMCode' 'ZipCode' 'ZoneDist1' 'ZoneDist2'
'ZoneDist3' 'ZoneDist4' 'ZoneMap' 'address' 'apartment_number' 'block'
'borough' 'building_class' 'building_class_at_sale'
'building_class_category' 'commercial_units' 'easement' 'gross_sqft'
'land_sqft' 'lot' 'neighborhood' 'price_range' 'residential_units'
'sale_date' 'tax_class' 'tax_class_at_sale' 'total_units' 'year_built'
'year_of_sale' 'zip_code'].
Reshape your data either using array.reshape(-1, 1) if your data has a single feature or array.reshape(1, -1) if it contains a single sample.
以下是我的数据示例:
housing_data = pd.DataFrame({'Unnamed: 0': {0: 1, 1: 2, 2: 3, 3: 4}, 'borough': {0: 3, 1: 3, 2: 3, 3: 3}, 'neighborhood': {0: 'DOWNTOWN-METROTECH', 1: 'DOWNTOWN-FULTON FERRY', 2: 'BROOKLYN HEIGHTS', 3: 'MILL BASIN'}, 'building_class_category': {0: '28 COMMERCIAL CONDOS', 1: '29 COMMERCIAL GARAGES', 2: '21 OFFICE BUILDINGS', 3: '22 STORE BUILDINGS'}, 'tax_class': {0: '4', 1: '4', 2: '4', 3: '4'}, 'block': {0: 140, 1: 54, 2: 204, 3: 8470}, 'lot': {0: 1001, 1: 1, 2: 1, 3: 55}, 'easement': {0: nan, 1: nan, 2: nan, 3: nan}, 'building_class': {0: 'R5', 1: 'G7', 2: 'O6', 3: 'K6'}, 'address': {0: '330 JAY STREET', 1: '85 JAY STREET', 2: '29 COLUMBIA HEIGHTS', 3: '5120 AVENUE U'}, 'apartment_number': {0: 'COURT', 1: nan, 2: nan, 3: nan}, 'zip_code': {0: 11201, 1: 11201, 2: 11201, 3: 11234}, 'residential_units': {0: 0, 1: 0, 2: 0, 3: 0}, 'commercial_units': {0: 1, 1: 0, 2: 0, 3: 123}, 'total_units': {0: 1, 1: 0, 2: 0, 3: 123}, 'land_sqft': {0: 0.0, 1: 134988.0, 2: 32000.0, 3: 905000.0}, 'gross_sqft': {0: 0.0, 1: 0.0, 2: 304650.0, 3: 2548000.0}, 'year_built': {0: 2002, 1: 0, 2: 1924, 3: 1970}, 'tax_class_at_sale': {0: 4, 1: 4, 2: 4, 3: 4}, 'building_class_at_sale': {0: 'R5', 1: 'G7', 2: 'O6', 3: 'K6'}, 'sale_price': {0: 499401179.0, 1: 345000000.0, 2: 340000000.0, 3: 276947000.0}, 'sale_date': {0: '2008-04-23', 1: '2016-12-20', 2: '2016-08-03', 3: '2012-11-28'}, 'year_of_sale': {0: 2008, 1: 2016, 2: 2016, 3: 2012}, 'Borough': {0: nan, 1: 'BK', 2: 'BK', 3: 'BK'}, 'CD': {0: nan, 1: 302.0, 2: 302.0, 3: 318.0}, 'CT2010': {0: nan, 1: 21.0, 2: 1.0, 3: 698.0}, 'CB2010': {0: nan, 1: 3017.0, 2: 1003.0, 3: 2005.0}, 'SchoolDist': {0: nan, 1: 13.0, 2: 13.0, 3: 22.0}, 'Council': {0: nan, 1: 33.0, 2: 33.0, 3: 46.0}, 'ZipCode': {0: nan, 1: 11201.0, 2: 11201.0, 3: 11234.0}, 'FireComp': {0: nan, 1: 'L118', 2: 'E205', 3: 'E323'}, 'PolicePrct': {0: nan, 1: 84.0, 2: 84.0, 3: 63.0}, 'HealthCent': {0: nan, 1: 36.0, 2: 38.0, 3: 35.0}, 'HealthArea': {0: nan, 1: 1000.0, 2: 2300.0, 3: 8822.0}, 'SanitBoro': {0: nan, 1: 3.0, 2: 3.0, 3: 3.0}, 'SanitDistr': {0: nan, 1: 2.0, 2: 2.0, 3: 18.0}, 'SanitSub': {0: nan, 1: '1B', 2: '1A', 3: '4E'}, 'Address': {0: nan, 1: '87 JAY STREET', 2: '29 COLUMBIA HEIGHTS', 3: '5120 AVENUE U'}, 'ZoneDist1': {0: nan, 1: 'M1-2/R8', 2: 'M2-1', 3: 'M3-1'}, 'ZoneDist2': {0: nan, 1: nan, 2: nan, 3: nan}, 'ZoneDist3': {0: nan, 1: nan, 2: nan, 3: nan}, 'ZoneDist4': {0: nan, 1: nan, 2: nan, 3: nan}, 'Overlay1': {0: nan, 1: nan, 2: nan, 3: nan}, 'Overlay2': {0: nan, 1: nan, 2: nan, 3: nan}, 'SPDist1': {0: nan, 1: 'MX-2', 2: nan, 3: nan}, 'SPDist2': {0: nan, 1: nan, 2: nan, 3: nan}, 'SPDist3': {0: nan, 1: nan, 2: nan, 3: nan}, 'LtdHeight': {0: nan, 1: nan, 2: nan, 3: nan}, 'SplitZone': {0: nan, 1: 'N', 2: 'N', 3: 'N'}, 'BldgClass': {0: nan, 1: 'G7', 2: 'O6', 3: 'K6'}, 'LandUse': {0: nan, 1: 10.0, 2: 5.0, 3: 5.0}, 'Easements': {0: nan, 1: 0.0, 2: 0.0, 3: 1.0}, 'OwnerType': {0: nan, 1: 'P', 2: nan, 3: nan}, 'OwnerName': {0: nan, 1: '85 JAY STREET BROOKLY', 2: '25-30 COLUMBIA HEIGHT', 3: 'BROOKLYN KINGS PLAZA'}, 'LotArea': {0: nan, 1: 134988.0, 2: 32000.0, 3: 905000.0}, 'BldgArea': {0: nan, 1: 0.0, 2: 304650.0, 3: 2548000.0}, 'ComArea': {0: nan, 1: 0.0, 2: 304650.0, 3: 2548000.0}, 'ResArea': {0: nan, 1: 0.0, 2: 0.0, 3: 0.0}, 'OfficeArea': {0: nan, 1: 0.0, 2: 264750.0, 3: 0.0}, 'RetailArea': {0: nan, 1: 0.0, 2: 0.0, 3: 1263000.0}, 'GarageArea': {0: nan, 1: 0.0, 2: 0.0, 3: 1285000.0}, 'StrgeArea': {0: nan, 1: 0.0, 2: 0.0, 3: 0.0}, 'FactryArea': {0: nan, 1: 0.0, 2: 0.0, 3: 0.0}, 'OtherArea': {0: nan, 1: 0.0, 2: 39900.0, 3: 0.0}, 'AreaSource': {0: nan, 1: 7.0, 2: 2.0, 3: 2.0}, 'NumBldgs': {0: nan, 1: 0.0, 2: 1.0, 3: 4.0}, 'NumFloors': {0: nan, 1: 0.0, 2: 13.0, 3: 2.0}, 'UnitsRes': {0: nan, 1: 0.0, 2: 0.0, 3: 0.0}, 'UnitsTotal': {0: nan, 1: 0.0, 2: 0.0, 3: 123.0}, 'LotFront': {0: nan, 1: 490.5, 2: 92.42, 3: 930.0}, 'LotDepth': {0: nan, 1: 275.33, 2: 335.92, 3: 859.0}, 'BldgFront': {0: nan, 1: 0.0, 2: 335.0, 3: 0.0}, 'BldgDepth': {0: nan, 1: 0.0, 2: 92.0, 3: 0.0}, 'Ext': {0: nan, 1: nan, 2: nan, 3: nan}, 'ProxCode': {0: nan, 1: 0.0, 2: 0.0, 3: 0.0}, 'IrrLotCode': {0: nan, 1: 'N', 2: 'Y', 3: 'Y'}, 'LotType': {0: nan, 1: 5.0, 2: 3.0, 3: 3.0}, 'BsmtCode': {0: nan, 1: 5.0, 2: 5.0, 3: 5.0}, 'AssessLand': {0: nan, 1: 1571850.0, 2: 1548000.0, 3: 36532350.0}, 'AssessTot': {0: nan, 1: 1571850.0, 2: 25463250.0, 3: 149792400.0}, 'ExemptLand': {0: nan, 1: 1571850.0, 2: 0.0, 3: 0.0}, 'ExemptTot': {0: nan, 1: 1571850.0, 2: 0.0, 3: 0.0}, 'YearBuilt': {0: nan, 1: 0.0, 2: 1924.0, 3: 1970.0}, 'YearAlter1': {0: nan, 1: 0.0, 2: 1980.0, 3: 0.0}, 'YearAlter2': {0: nan, 1: 0.0, 2: 0.0, 3: 0.0}, 'HistDist': {0: nan, 1: nan, 2: nan, 3: nan}, 'Landmark': {0: nan, 1: nan, 2: nan, 3: nan}, 'BuiltFAR': {0: nan, 1: 0.0, 2: 9.52, 3: 2.82}, 'ResidFAR': {0: nan, 1: 7.2, 2: 0.0, 3: 0.0}, 'CommFAR': {0: nan, 1: 2.0, 2: 2.0, 3: 2.0}, 'FacilFAR': {0: nan, 1: 6.5, 2: 0.0, 3: 0.0}, 'BoroCode': {0: nan, 1: 3.0, 2: 3.0, 3: 3.0}, 'BBL': {0: nan, 1: 3000540001.0, 2: 3002040001.0, 3: 3084700055.0}, 'CondoNo': {0: nan, 1: 0.0, 2: 0.0, 3: 0.0}, 'Tract2010': {0: nan, 1: 21.0, 2: 1.0, 3: 698.0}, 'XCoord': {0: nan, 1: 988208.0, 2: 985952.0, 3: 1006597.0}, 'YCoord': {0: nan, 1: 195011.0, 2: 195007.0, 3: 161424.0}, 'ZoneMap': {0: nan, 1: '12d', 2: '12d', 3: '23b'}, 'ZMCode': {0: nan, 1: nan, 2: nan, 3: nan}, 'Sanborn': {0: nan, 1: '302 016', 2: '302 004', 3: '319 077'}, 'TaxMap': {0: nan, 1: 30101.0, 2: 30106.0, 3: 32502.0}, 'EDesigNum': {0: nan, 1: nan, 2: nan, 3: nan}, 'APPBBL': {0: nan, 1: 3000540001.0, 2: 0.0, 3: 0.0}, 'APPDate': {0: nan, 1: '12/06/2002', 2: nan, 3: nan}, 'PLUTOMapID': {0: nan, 1: 1.0, 2: 1.0, 3: 1.0}, 'FIRM07_FLA': {0: nan, 1: nan, 2: nan, 3: 1.0}, 'PFIRM15_FL': {0: nan, 1: nan, 2: nan, 3: 1.0}, 'Version': {0: nan, 1: '17V1.1', 2: '17V1.1', 3: '17V1.1'}, 'MAPPLUTO_F': {0: nan, 1: 0.0, 2: 0.0, 3: 0.0}, 'SHAPE_Leng': {0: nan, 1: 1559.88914353, 2: 890.718521021, 3: 3729.78685686}, 'SHAPE_Area': {0: nan, 1: 140131.577176, 2: 34656.4472405, 3: 797554.847834}, 'price_range': {0: nan, 1: nan, 2: nan, 3: nan}})
推荐答案
转换器需要一个2D数组，形状为(nxm)，其中n是样本数，m是特征数，如果您看一下形状， features我想它将显示:(m,).
The transformer expects a 2D array, of shape (n x m) where n is the number of samples and m the number of features and if you look at the shape of features I imagine it will display: (m,).
重塑数组
通常，对于形状为(n,)的特征数组，可以按照错误代码的建议进行操作，并在特征数组上调用.reshape(-1,1)，-1使其变为
In general for a feature array of shape (n,), you can do as the error code suggests and call .reshape(-1,1) on your feature array, the -1 lets it infer the additional dimension: The shape of the array will be (n,m), where for a 1 feature case m = 1.
Sklearn变压器
以上所述，我认为您的代码和理解上还有其他错误.
The above being said, I think there is additional errors with your code and understanding.
我将打印features到屏幕上并检查它是否是您想要的，看起来您正在打印除sale_price以外的所有列名称的 list .
我不熟悉 SelectKBest ，但它需要(n,m)功能 array ，而不是功能列名称的列表.
I would print features to screen and check it is what you want, it looks like you are printing a list of all the column names except sale_price.
I am not familiar with SelectKBest but it requires an (n,m) feature array not a list of column names of the features.
此外，target不应是目标列的名称，而应是形状为(n,)的数组，其中的值是训练实例观察到的目标值.
Additionally, target should not be the name of the target column, but an array of shape (n,), where its values are the observed target values of the training instances.
我建议在编写代码时检查文档(以前参考)，以确保使用正确的参数并按预期使用函数.
I would suggest checking the documentation (previously referenced) while you are writing your code to make sure you are using the correct arguments and utilising the function as it is intended.
提取功能
您的数据似乎采用了奇怪的格式(字典嵌套在熊猫DF中).但是，这是一个明确的示例，说明了如何从pd.DataFrame提取特征以与SKlearn框架中的函数一起使用.
Your data seems in a strange format (dictionary's nested in a pandas DF). However is a explicit example of how I would extract features from a pd.DataFrame for use with functions from the SKlearn framework.
housing_data = pd.DataFrame({'age': [1,5,1,10], 'size':[0,1,2,0],
'price':[190,100,50,100]
})
feature_arr = housing_data.drop('price', axis=1).values
target_values = housing_data['price']
打印feature_arr，希望您会看到您的问题.通常，您必须进行预处理，例如，删除NaN值或执行特征缩放.
Print feature_arr and you will hopefully see your issue. Normally you would then have to preprocess the data to, for example, drop NaN values or perform feature scaling.
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