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# EXAMPLE SEE http://scikit-learn.org/stable/auto_examples/feature_stacker.html#sphx-glr-auto-examples-feature-stacker-py

In [1]:
# Author: Andreas Mueller <amueller@ais.uni-bonn.de>
#
# License: BSD 3 clause

from sklearn.pipeline import Pipeline, FeatureUnion
from sklearn.model_selection import GridSearchCV
from sklearn.svm import SVC
from sklearn.datasets import load_iris
from sklearn.decomposition import PCA
from sklearn.feature_selection import SelectKBest

iris = load_iris()

X, y = iris.data, iris.target

# This dataset is way too high-dimensional. Better do PCA:
pca = PCA(n_components=2)

# Maybe some original features where good, too?
selection = SelectKBest(k=1)

# Build estimator from PCA and Univariate selection:

combined_features = FeatureUnion([("pca", pca), ("univ_select", selection)])

# Use combined features to transform dataset:
X_features = combined_features.fit(X, y).transform(X)

svm = SVC(kernel="linear")

# Do grid search over k, n_components and C:

pipeline = Pipeline([("features", combined_features), ("svm", svm)])

param_grid = dict(features__pca__n_components=[1, 2, 3],
                  features__univ_select__k=[1, 2],
                  svm__C=[0.1, 1, 10])

grid_search = GridSearchCV(pipeline, param_grid=param_grid, verbose=10)
grid_search.fit(X, y)
print(grid_search.best_estimator_)


Fitting 3 folds for each of 18 candidates, totalling 54 fits
[CV] features__pca__n_components=1, svm__C=0.1, features__univ_select__k=1 
[CV]  features__pca__n_components=1, svm__C=0.1, features__univ_select__k=1, score=0.960784 -   0.0s
[CV] features__pca__n_components=1, svm__C=0.1, features__univ_select__k=1 
[CV]  features__pca__n_components=1, svm__C=0.1, features__univ_select__k=1, score=0.901961 -   0.0s
[CV] features__pca__n_components=1, svm__C=0.1, features__univ_select__k=1 
[CV]  features__pca__n_components=1, svm__C=0.1, features__univ_select__k=1, score=0.979167 -   0.0s
[CV] features__pca__n_components=1, svm__C=1, features__univ_select__k=1 
[CV]  features__pca__n_components=1, svm__C=1, features__univ_select__k=1, score=0.941176 -   0.0s
[CV] features__pca__n_components=1, svm__C=1, features__univ_select__k=1 
[CV]  features__pca__n_components=1, svm__C=1, features__univ_select__k=1, score=0.921569 -   0.0s
[CV] features__pca__n_components=1, svm__C=1, features__univ_select__k=1 
[CV]  features__pca__n_components=1, svm__C=1, features__univ_select__k=1, score=0.979167 -   0.0s
[CV] features__pca__n_components=1, svm__C=10, features__univ_select__k=1 
[CV]  features__pca__n_components=1, svm__C=10, features__univ_select__k=1, score=0.960784 -   0.0s
[CV] features__pca__n_components=1, svm__C=10, features__univ_select__k=1 
[CV]  features__pca__n_components=1, svm__C=10, features__univ_select__k=1, score=0.921569 -   0.0s
[CV] features__pca__n_components=1, svm__C=10, features__univ_select__k=1 
[CV]  features__pca__n_components=1, svm__C=10, features__univ_select__k=1, score=0.979167 -   0.0s
[CV] features__pca__n_components=1, svm__C=0.1, features__univ_select__k=2 
[CV]  features__pca__n_components=1, svm__C=0.1, features__univ_select__k=2, score=0.960784 -   0.0s
[CV] features__pca__n_components=1, svm__C=0.1, features__univ_select__k=2 
[CV]  features__pca__n_components=1, svm__C=0.1, features__univ_select__k=2, score=0.921569 -   0.0s
[CV] features__pca__n_components=1, svm__C=0.1, features__univ_select__k=2 
[CV]  features__pca__n_components=1, svm__C=0.1, features__univ_select__k=2, score=0.979167 -   0.0s
[CV] features__pca__n_components=1, svm__C=1, features__univ_select__k=2 
[CV]  features__pca__n_components=1, svm__C=1, features__univ_select__k=2, score=0.960784 -   0.0s
[CV] features__pca__n_components=1, svm__C=1, features__univ_select__k=2 
[CV]  features__pca__n_components=1, svm__C=1, features__univ_select__k=2, score=0.921569 -   0.0s
[CV] features__pca__n_components=1, svm__C=1, features__univ_select__k=2 
[CV]  features__pca__n_components=1, svm__C=1, features__univ_select__k=2, score=1.000000 -   0.0s
[CV] features__pca__n_components=1, svm__C=10, features__univ_select__k=2 
[CV]  features__pca__n_components=1, svm__C=10, features__univ_select__k=2, score=0.980392 -   0.0s
[CV] features__pca__n_components=1, svm__C=10, features__univ_select__k=2 
[CV]  features__pca__n_components=1, svm__C=10, features__univ_select__k=2, score=0.901961 -   0.0s
[CV] features__pca__n_components=1, svm__C=10, features__univ_select__k=2 
[CV]  features__pca__n_components=1, svm__C=10, features__univ_select__k=2, score=1.000000 -   0.0s
[CV] features__pca__n_components=2, svm__C=0.1, features__univ_select__k=1 
[CV]  features__pca__n_components=2, svm__C=0.1, features__univ_select__k=1, score=0.960784 -   0.0s
[CV] features__pca__n_components=2, svm__C=0.1, features__univ_select__k=1 
[CV]  features__pca__n_components=2, svm__C=0.1, features__univ_select__k=1, score=0.901961 -   0.0s
[CV] features__pca__n_components=2, svm__C=0.1, features__univ_select__k=1 
[CV]  features__pca__n_components=2, svm__C=0.1, features__univ_select__k=1, score=0.979167 -   0.0s
[CV] features__pca__n_components=2, svm__C=1, features__univ_select__k=1 
[CV]  features__pca__n_components=2, svm__C=1, features__univ_select__k=1, score=0.980392 -   0.0s
[CV] features__pca__n_components=2, svm__C=1, features__univ_select__k=1 
[CV]  features__pca__n_components=2, svm__C=1, features__univ_select__k=1, score=0.941176 -   0.0s
[Parallel(n_jobs=1)]: Done   1 out of   1 | elapsed:    0.0s remaining:    0.0s
[Parallel(n_jobs=1)]: Done   2 out of   2 | elapsed:    0.0s remaining:    0.0s
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[Parallel(n_jobs=1)]: Done   6 out of   6 | elapsed:    0.1s remaining:    0.0s
[Parallel(n_jobs=1)]: Done   7 out of   7 | elapsed:    0.1s remaining:    0.0s
[Parallel(n_jobs=1)]: Done   8 out of   8 | elapsed:    0.1s remaining:    0.0s
[Parallel(n_jobs=1)]: Done   9 out of   9 | elapsed:    0.1s remaining:    0.0s
[CV] features__pca__n_components=2, svm__C=1, features__univ_select__k=1 
[CV]  features__pca__n_components=2, svm__C=1, features__univ_select__k=1, score=0.979167 -   0.0s
[CV] features__pca__n_components=2, svm__C=10, features__univ_select__k=1 
[CV]  features__pca__n_components=2, svm__C=10, features__univ_select__k=1, score=0.980392 -   0.0s
[CV] features__pca__n_components=2, svm__C=10, features__univ_select__k=1 
[CV]  features__pca__n_components=2, svm__C=10, features__univ_select__k=1, score=0.941176 -   0.0s
[CV] features__pca__n_components=2, svm__C=10, features__univ_select__k=1 
[CV]  features__pca__n_components=2, svm__C=10, features__univ_select__k=1, score=0.979167 -   0.0s
[CV] features__pca__n_components=2, svm__C=0.1, features__univ_select__k=2 
[CV]  features__pca__n_components=2, svm__C=0.1, features__univ_select__k=2, score=0.980392 -   0.0s
[CV] features__pca__n_components=2, svm__C=0.1, features__univ_select__k=2 
[CV]  features__pca__n_components=2, svm__C=0.1, features__univ_select__k=2, score=0.941176 -   0.0s
[CV] features__pca__n_components=2, svm__C=0.1, features__univ_select__k=2 
[CV]  features__pca__n_components=2, svm__C=0.1, features__univ_select__k=2, score=0.979167 -   0.0s
[CV] features__pca__n_components=2, svm__C=1, features__univ_select__k=2 
[CV]  features__pca__n_components=2, svm__C=1, features__univ_select__k=2, score=1.000000 -   0.0s
[CV] features__pca__n_components=2, svm__C=1, features__univ_select__k=2 
[CV]  features__pca__n_components=2, svm__C=1, features__univ_select__k=2, score=0.960784 -   0.0s
[CV] features__pca__n_components=2, svm__C=1, features__univ_select__k=2 
[CV]  features__pca__n_components=2, svm__C=1, features__univ_select__k=2, score=0.979167 -   0.0s
[CV] features__pca__n_components=2, svm__C=10, features__univ_select__k=2 
[CV]  features__pca__n_components=2, svm__C=10, features__univ_select__k=2, score=0.980392 -   0.0s
[CV] features__pca__n_components=2, svm__C=10, features__univ_select__k=2 
[CV]  features__pca__n_components=2, svm__C=10, features__univ_select__k=2, score=0.921569 -   0.0s
[CV] features__pca__n_components=2, svm__C=10, features__univ_select__k=2 
[CV]  features__pca__n_components=2, svm__C=10, features__univ_select__k=2, score=1.000000 -   0.0s
[CV] features__pca__n_components=3, svm__C=0.1, features__univ_select__k=1 
[CV]  features__pca__n_components=3, svm__C=0.1, features__univ_select__k=1, score=0.980392 -   0.0s
[CV] features__pca__n_components=3, svm__C=0.1, features__univ_select__k=1 
[CV]  features__pca__n_components=3, svm__C=0.1, features__univ_select__k=1, score=0.941176 -   0.0s
[CV] features__pca__n_components=3, svm__C=0.1, features__univ_select__k=1 
[CV]  features__pca__n_components=3, svm__C=0.1, features__univ_select__k=1, score=0.979167 -   0.0s
[CV] features__pca__n_components=3, svm__C=1, features__univ_select__k=1 
[CV]  features__pca__n_components=3, svm__C=1, features__univ_select__k=1, score=1.000000 -   0.0s
[CV] features__pca__n_components=3, svm__C=1, features__univ_select__k=1 
[CV]  features__pca__n_components=3, svm__C=1, features__univ_select__k=1, score=0.941176 -   0.0s
[CV] features__pca__n_components=3, svm__C=1, features__univ_select__k=1 
[CV]  features__pca__n_components=3, svm__C=1, features__univ_select__k=1, score=0.979167 -   0.0s
[CV] features__pca__n_components=3, svm__C=10, features__univ_select__k=1 
[CV]  features__pca__n_components=3, svm__C=10, features__univ_select__k=1, score=1.000000 -   0.0s
[CV] features__pca__n_components=3, svm__C=10, features__univ_select__k=1 
[CV]  features__pca__n_components=3, svm__C=10, features__univ_select__k=1, score=0.921569 -   0.0s
[CV] features__pca__n_components=3, svm__C=10, features__univ_select__k=1 
[CV]  features__pca__n_components=3, svm__C=10, features__univ_select__k=1, score=1.000000 -   0.0s
[CV] features__pca__n_components=3, svm__C=0.1, features__univ_select__k=2 
[CV]  features__pca__n_components=3, svm__C=0.1, features__univ_select__k=2, score=0.980392 -   0.0s
[CV] features__pca__n_components=3, svm__C=0.1, features__univ_select__k=2 
[CV]  features__pca__n_components=3, svm__C=0.1, features__univ_select__k=2, score=0.941176 -   0.0s
[CV] features__pca__n_components=3, svm__C=0.1, features__univ_select__k=2 
[CV]  features__pca__n_components=3, svm__C=0.1, features__univ_select__k=2, score=0.979167 -   0.0s
[CV] features__pca__n_components=3, svm__C=1, features__univ_select__k=2 
[CV]  features__pca__n_components=3, svm__C=1, features__univ_select__k=2, score=1.000000 -   0.0s
[CV] features__pca__n_components=3, svm__C=1, features__univ_select__k=2 
[CV]  features__pca__n_components=3, svm__C=1, features__univ_select__k=2, score=0.960784 -   0.0s
[CV] features__pca__n_components=3, svm__C=1, features__univ_select__k=2 
[CV]  features__pca__n_components=3, svm__C=1, features__univ_select__k=2, score=0.979167 -   0.0s
[CV] features__pca__n_components=3, svm__C=10, features__univ_select__k=2 
[CV]  features__pca__n_components=3, svm__C=10, features__univ_select__k=2, score=1.000000 -   0.0s
[CV] features__pca__n_components=3, svm__C=10, features__univ_select__k=2 
[CV]  features__pca__n_components=3, svm__C=10, features__univ_select__k=2, score=0.921569 -   0.0s
[CV] features__pca__n_components=3, svm__C=10, features__univ_select__k=2 
[CV]  features__pca__n_components=3, svm__C=10, features__univ_select__k=2, score=1.000000 -   0.0s
Pipeline(steps=[('features', FeatureUnion(n_jobs=1,
       transformer_list=[('pca', PCA(copy=True, iterated_power='auto', n_components=2, random_state=None,
  svd_solver='auto', tol=0.0, whiten=False)), ('univ_select', SelectKBest(k=2, score_func=<function f_classif at 0x7f5b02dc8048>))],
       transformer...,
  max_iter=-1, probability=False, random_state=None, shrinking=True,
  tol=0.001, verbose=False))])
[Parallel(n_jobs=1)]: Done  54 out of  54 | elapsed:    0.7s finished

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