带管道和GridSearchCV的StandardScaler

Question

我已经在管道上安装了standardScaler，并且预测CV_mlpregression(x_test(的结果是怪异的。我想我必须从标准Scaler中恢复值，但仍然不知道如何恢复。

pipe_MLPRegressor = Pipeline([('scaler',  StandardScaler()),
('MLPRegressor', MLPRegressor(random_state = 42))])

grid_params_MLPRegressor = [{
'MLPRegressor__solver': ['lbfgs'],
'MLPRegressor__max_iter': [100,200,300,500],
'MLPRegressor__activation' : ['relu','logistic','tanh'],
'MLPRegressor__hidden_layer_sizes':[(2,), (4,),(2,2),(4,4),(4,2),(10,10),(2,2,2)],
}]

CV_mlpregressor = GridSearchCV (estimator = pipe_MLPRegressor,
param_grid = grid_params_MLPRegressor,
cv = 5,return_train_score=True, verbose=0)
CV_mlpregressor.fit(x_train, y_train)
CV_mlpregressor.predict(x_test)

结果：

array([ 2.67564153e+04,  1.90010572e+04,  9.62702942e+04,  3.98791931e+04,
1.48889808e+03,  7.08980726e+03,  3.86311279e+02,  7.05602301e+04,
4.06858486e+03,  4.29186303e+04,  3.86701735e+03,  6.30228075e+04,
6.78276925e+04, -5.91956287e+02, -7.37680434e+02,  3.07485001e+04,
4.81417953e+03,  5.18697686e+03,  1.61221952e+04,  1.33794944e+04,
-1.48375101e+03,  1.80891807e+04,  1.39740243e+04,  6.57156849e+04,
3.32962481e+04,  5.71332087e+05,  1.79130092e+03,  5.25642370e+04,
2.08111172e+04,  4.31060127e+04])

提前谢谢。

Answer 1

@Lian，我认为你做每件事的方式都是正确的。请检查您的数据。我用sklearn数据集做了一个实验，结果不出所料。

from sklearn.preprocessing import StandardScaler
from sklearn.neural_network import MLPRegressor
from sklearn.pipeline import Pipeline
from sklearn.model_selection import GridSearchCV
from sklearn.datasets import load_boston
from sklearn.model_selection import train_test_split
import numpy as np
x,y = load_boston(return_X_y=True)

xtrain, xtest, ytrain, ytest = train_test_split(x,y, random_state=6784)
pipe_MLPRegressor = Pipeline([('scaler',  StandardScaler()),
('MLPRegressor', MLPRegressor(random_state = 42))])
grid_params_MLPRegressor = [{
'MLPRegressor__solver': ['lbfgs'],
'MLPRegressor__max_iter': [100,200,300,500],
'MLPRegressor__activation' : ['relu','logistic','tanh'],
'MLPRegressor__hidden_layer_sizes':[(2,), (4,),(2,2),(4,4),(4,2),(10,10),(2,
2,2)],}]

CV_mlpregressor = GridSearchCV (estimator = pipe_MLPRegressor,
param_grid = grid_params_MLPRegressor,
cv = 5,return_train_score=True, verbose=0)
CV_mlpregressor.fit(xtrain, ytrain)
ypred=CV_mlpregressor.predict(xtest)
print np.c_[ytest, ypred]

这将打印

array([[ 29.9       ,  30.79749986],
[ 22.5       ,  24.52180656],
[ 22.6       ,  18.9567779 ],
[ 28.7       ,  22.17189123],
[ 13.8       ,  19.16797811],
[ 21.2       ,  24.63527335],
[ 11.3       ,  13.58962076],
[ 23.        ,  18.33693455],
[ 12.7       ,  15.52294714],
[ 23.3       ,  26.65083451],
[ 25.3       ,  24.04219813],
[ 22.6       ,  19.81454969],
[ 36.2       ,  22.16994764],
[ 17.9       ,  11.1221789 ],
[ 18.5       ,  17.84162452],
[ 16.8       ,  22.99832673],
[ 20.3       ,  20.22598426],
[ 23.9       ,  26.80997945],
[ 17.6       ,  16.08188321],
[ 23.2       ,  18.5995955 ],
[ 48.3       ,  43.37911488],
[ 19.1       ,  22.36379857],