def featureFitting(filename,
X,
y,
featureNames,
optimalFlag,
kbest=20,
alpha=0.05,
model=None):
'''
Gets the K-best features (filtered by FDR, then select best ranked by t-test, more advanced options can be implemented).
Save the data/matrix with the resulting/kept features to a new output file, "REDUCED_Feat.csv"
Returns new features matrix, FD scaler, and K-select scaler
'''
a = alpha
FD = SelectFdr(alpha=a)
X = FD.fit_transform(X, y)
selectK = SelectKBest(k=kbest)
selectK.fit(X, y)
selectK_mask = selectK.get_support()
K_featnames = featureNames[selectK_mask]
print("K_featnames: %s" % (K_featnames))
Reduced_df = pd.read_csv(filename, index_col=0)
Reduced_df = Reduced_df[Reduced_df.columns[selectK_mask]]
Reduced_df.to_csv('REDUCED_Feat.csv')
return Reduced_df, FD, selectK
def single_fdr(alpha, n_informative, random_state):
X, y = make_regression(n_samples=150,
n_features=20,
n_informative=n_informative,
shuffle=False,
random_state=random_state,
noise=10)
with warnings.catch_warnings(record=True):
# Warnings can be raised when no features are selected
# (low alpha or very noisy data)
univariate_filter = SelectFdr(f_regression, alpha=alpha)
X_r = univariate_filter.fit(X, y).transform(X)
X_r2 = GenericUnivariateSelect(f_regression,
mode='fdr',
param=alpha).fit(X, y).transform(X)
assert_array_equal(X_r, X_r2)
support = univariate_filter.get_support()
num_false_positives = np.sum(support[n_informative:] == 1)
num_true_positives = np.sum(support[:n_informative] == 1)
if num_false_positives == 0:
return 0.
false_discovery_rate = (num_false_positives /
(num_true_positives + num_false_positives))
return false_discovery_rate
class f_regressionFDRPrim(primitive):
def __init__(self, random_state=0):
super(f_regressionFDRPrim, self).__init__(name='f_regressionFDR')
self.id = 34
self.PCA_LAPACK_Prim = []
self.type = 'feature selection'
self.description = "Filter: Select the p-values for an estimated false discovery rate with F-value between label/feature for regression tasks. This uses the Benjamini-Hochberg procedure. alpha is an upper bound on the expected false discovery rate."
self.hyperparams_run = {'default': True}
self.selector = None
self.accept_type = 'c_r'
def can_accept(self, data):
return self.can_accept_c(data, 'Regression')
def is_needed(self, data):
if data['X'].shape[1] < 3:
return False
return True
def fit(self, data):
data = handle_data(data)
self.selector = SelectFdr(f_regression)
self.selector.fit(data['X'], data['Y'])
def produce(self, data):
output = handle_data(data)
cols = list(output['X'].columns)
mask = self.selector.get_support(indices=False)
final_cols = list(compress(cols, mask))
output['X'] = pd.DataFrame(self.selector.transform(output['X']), columns=final_cols)
final_output = {0: output}
return final_output
class UnivariateSelectChiFDRPrim(primitive):
def __init__(self, random_state=0):
super(UnivariateSelectChiFDRPrim, self).__init__(name='UnivariateSelectChiFDR')
self.id = 31
self.PCA_LAPACK_Prim = []
self.type = 'feature selection'
self.description = "Filter: Select the p-values for an estimated false discovery rate with Chi-square. This uses the Benjamini-Hochberg procedure. alpha is an upper bound on the expected false discovery rate."
self.hyperparams_run = {'default': True}
self.selector = None
self.accept_type = 'd'
def can_accept(self, data):
return self.can_accept_d(data, 'Classification')
def is_needed(self, data):
if data['X'].shape[1] < 3:
return False
return True
def fit(self, data):
data = handle_data(data)
self.selector = SelectFdr(chi2, alpha=0.05)
self.selector.fit(data['X'], data['Y'])
def produce(self, data):
output = handle_data(data)
cols = list(output['X'].columns)
try:
mask = self.selector.get_support(indices=False)
final_cols = list(compress(cols, mask))
output['X'] = pd.DataFrame(self.selector.transform(output['X']), columns=final_cols)
except Exception as e:
print(e)
final_output = {0: output}
return final_output
def test_boundary_case_ch2():
# Test boundary case, and always aim to select 1 feature.
X = np.array([[10, 20], [20, 20], [20, 30]])
y = np.array([[1], [0], [0]])
scores, pvalues = chi2(X, y)
assert_array_almost_equal(scores, np.array([4., 0.71428571]))
assert_array_almost_equal(pvalues, np.array([0.04550026, 0.39802472]))
filter_fdr = SelectFdr(chi2, alpha=0.1)
filter_fdr.fit(X, y)
support_fdr = filter_fdr.get_support()
assert_array_equal(support_fdr, np.array([True, False]))
filter_kbest = SelectKBest(chi2, k=1)
filter_kbest.fit(X, y)
support_kbest = filter_kbest.get_support()
assert_array_equal(support_kbest, np.array([True, False]))
filter_percentile = SelectPercentile(chi2, percentile=50)
filter_percentile.fit(X, y)
support_percentile = filter_percentile.get_support()
assert_array_equal(support_percentile, np.array([True, False]))
filter_fpr = SelectFpr(chi2, alpha=0.1)
filter_fpr.fit(X, y)
support_fpr = filter_fpr.get_support()
assert_array_equal(support_fpr, np.array([True, False]))
filter_fwe = SelectFwe(chi2, alpha=0.1)
filter_fwe.fit(X, y)
support_fwe = filter_fwe.get_support()
assert_array_equal(support_fwe, np.array([True, False]))
def test_select_fdr_classif():
"""
Test whether the relative univariate feature selection
gets the correct items in a simple classification problem
with the fpr heuristic
"""
X, Y = make_classification(
n_samples=200,
n_features=20,
n_informative=3,
n_redundant=2,
n_repeated=0,
n_classes=8,
n_clusters_per_class=1,
flip_y=0.0,
class_sep=10,
shuffle=False,
random_state=0,
)
univariate_filter = SelectFdr(f_classif, alpha=0.0001)
X_r = univariate_filter.fit(X, Y).transform(X)
X_r2 = GenericUnivariateSelect(f_classif, mode="fdr", param=0.0001).fit(X, Y).transform(X)
assert_array_equal(X_r, X_r2)
support = univariate_filter.get_support()
gtruth = np.zeros(20)
gtruth[:5] = 1
assert_array_equal(support, gtruth)
def single_fdr(alpha, n_informative, random_state):
X, y = make_regression(
n_samples=150,
n_features=20,
n_informative=n_informative,
shuffle=False,
random_state=random_state,
noise=10,
)
with warnings.catch_warnings(record=True):
# Warnings can be raised when no features are selected
# (low alpha or very noisy data)
univariate_filter = SelectFdr(f_regression, alpha=alpha)
X_r = univariate_filter.fit(X, y).transform(X)
X_r2 = GenericUnivariateSelect(f_regression, mode="fdr", param=alpha).fit(X, y).transform(X)
assert_array_equal(X_r, X_r2)
support = univariate_filter.get_support()
num_false_positives = np.sum(support[n_informative:] == 1)
num_true_positives = np.sum(support[:n_informative] == 1)
if num_false_positives == 0:
return 0.0
false_discovery_rate = num_false_positives / (num_true_positives + num_false_positives)
return false_discovery_rate
def test_boundary_case_ch2():
# Test boundary case, and always aim to select 1 feature.
X = np.array([[10, 20], [20, 20], [20, 30]])
y = np.array([[1], [0], [0]])
scores, pvalues = chi2(X, y)
assert_array_almost_equal(scores, np.array([4.0, 0.71428571]))
assert_array_almost_equal(pvalues, np.array([0.04550026, 0.39802472]))
filter_fdr = SelectFdr(chi2, alpha=0.1)
filter_fdr.fit(X, y)
support_fdr = filter_fdr.get_support()
assert_array_equal(support_fdr, np.array([True, False]))
filter_kbest = SelectKBest(chi2, k=1)
filter_kbest.fit(X, y)
support_kbest = filter_kbest.get_support()
assert_array_equal(support_kbest, np.array([True, False]))
filter_percentile = SelectPercentile(chi2, percentile=50)
filter_percentile.fit(X, y)
support_percentile = filter_percentile.get_support()
assert_array_equal(support_percentile, np.array([True, False]))
filter_fpr = SelectFpr(chi2, alpha=0.1)
filter_fpr.fit(X, y)
support_fpr = filter_fpr.get_support()
assert_array_equal(support_fpr, np.array([True, False]))
filter_fwe = SelectFwe(chi2, alpha=0.1)
filter_fwe.fit(X, y)
support_fwe = filter_fwe.get_support()
assert_array_equal(support_fwe, np.array([True, False]))
def gene_univariate_feature_selection(self, alpha=0.01):
gene_normal_X, gene_normal_Y = self.make_dataset(
dataset='gene',
normal_tumor='normal',
normal_matched=True,
mirna_gene_matched=True)
gene_tumor_X, gene_tumor_Y = self.make_dataset(dataset='gene',
normal_tumor='tumor',
normal_matched=True,
mirna_gene_matched=True)
gene_exp_filter = SelectFdr(f_classif, alpha=alpha)
gen_exp_new = gene_exp_filter.fit_transform(
X=pandas.concat([gene_normal_X, gene_tumor_X]),
y=pandas.concat([gene_normal_Y, gene_tumor_Y]))
self.gene_symbols = np.asanyarray(
self.gene_symbols)[gene_exp_filter.get_support(
indices=True)].tolist()
self.gene_tumor = self.gene_tumor[
self.gene_symbols +
['patient_barcode', 'pathologic_stage', 'histological_type']]
self.gene_normal = self.gene_normal[
self.gene_symbols +
['patient_barcode', 'pathologic_stage', 'histological_type']]
def test_select_fdr_classif():
"""
Test whether the relative univariate feature selection
gets the correct items in a simple classification problem
with the fpr heuristic
"""
X, y = make_classification(n_samples=200,
n_features=20,
n_informative=3,
n_redundant=2,
n_repeated=0,
n_classes=8,
n_clusters_per_class=1,
flip_y=0.0,
class_sep=10,
shuffle=False,
random_state=0)
univariate_filter = SelectFdr(f_classif, alpha=0.0001)
X_r = univariate_filter.fit(X, y).transform(X)
X_r2 = GenericUnivariateSelect(f_classif, mode='fdr',
param=0.0001).fit(X, y).transform(X)
assert_array_equal(X_r, X_r2)
support = univariate_filter.get_support()
gtruth = np.zeros(20)
gtruth[:5] = 1
assert_array_equal(support, gtruth)
def test_pipeline():
pipeline = dl.Pipeline([("scale", StandardScaler()), ("fdr", SelectFdr()),
("svm", LinearSVC())])
pipeline = pipeline.fit(X, y)
y2 = pipeline.predict(X)
score = pipeline.score(X, y)
assert isinstance(y2, di.Value)
assert isinstance(score, di.Value)
assert isinstance(score.compute(), float)
assert pipeline.score(X, y).key == pipeline.score(X, y).key
assert score.compute() == score.compute()
y22 = y2.compute()
assert y22.shape == y.shape
assert y22.dtype == y.dtype
skpipeline = sklearn.pipeline.Pipeline([("scale", StandardScaler()),
("fdr", SelectFdr()),
("svm", LinearSVC())])
skpipeline.fit(X, y)
sk_y2 = skpipeline.predict(X)
sk_score = skpipeline.score(X, y)
assert sk_score == score.compute()
def SelectFdr_selector(data, target, sf):
selector = SelectFdr(score_func=sf)
data_new = selector.fit_transform(data.values, target.values.ravel())
outcome = selector.get_support(True)
new_features = [] # The list of your K best features
for ind in outcome:
new_features.append(data.columns.values[ind])
return pd.DataFrame(data_new, columns=new_features)
def feature_SelectFdr(x_data, y_data):
bestfeatures = SelectFdr(f_classif, alpha=0.01)
fit = bestfeatures.fit(x_data, y_data)
dfscores = pd.DataFrame(fit.scores_)
dfcolumns = pd.DataFrame(x_data.columns)
featureScores = pd.concat([dfcolumns, dfscores], axis=1)
featureScores.columns = ['Specs', 'Score'] # naming the dataframe columns
top_20_features = featureScores.nlargest(20, 'Score')
return top_20_features
def feature_select(labels, features, alfa=0.4):
dct = DecisionTreeClassifier(random_state=42)
rfecv1 = RFECV(estimator=dct,
step=1,
cv=StratifiedKFold(labels,
n_folds=6,
shuffle=True,
random_state=42),
scoring='recall')
rfecv2 = RFECV(estimator=dct,
step=1,
cv=StratifiedKFold(labels,
n_folds=6,
shuffle=True,
random_state=42),
scoring='precision')
rfecv1.fit(features, labels)
rfecv2.fit(features, labels)
print("Optimal number of features - Recall : %d" % rfecv1.n_features_)
print("Optimal number of features - Precision : %d" % rfecv2.n_features_)
BestFeatures = SelectFdr(score_func=f_classif, alpha=alfa)
BestFeatures.fit_transform(features, labels)
# BestFeatures = SelectKBest(score_func=f_classif,k=numbest)
# BestFeatures.fit_transform(features,labels)
feature_scores = BestFeatures.scores_
feature_pvalues = BestFeatures.pvalues_
best_feat_indices = BestFeatures.get_support(indices=True)
best_list = []
for i in range(len(best_feat_indices)):
best_list.append(features_list[best_feat_indices[i] + 1])
print 'Best features:', best_list
feat_ctr = -1
for index in best_feat_indices:
feat_ctr += 1
print best_list[feat_ctr], 'Score:', feature_scores[
index], 'P-value:', feature_pvalues[index]
plt.figure()
plt.xlabel("Number of features selected")
plt.ylabel("Recall & Precision")
plt.plot(range(1,
len(rfecv1.grid_scores_) + 1),
rfecv1.grid_scores_,
label='Recall',
color='blue')
plt.plot(range(1,
len(rfecv2.grid_scores_) + 1),
rfecv2.grid_scores_,
label='Precision',
color='green')
plt.legend()
plt.show()
def test_select_fdr_int(self):
model = SelectFdr()
X, y = load_breast_cancer(return_X_y=True)
model.fit(X, y)
model_onnx = convert_sklearn(
model, "select fdr",
[("input", Int64TensorType([None, X.shape[1]]))],
target_opset=TARGET_OPSET)
self.assertTrue(model_onnx is not None)
dump_data_and_model(
X.astype(np.int64), model, model_onnx,
basename="SklearnSelectFdr")
def test_select_fdr_int(self):
model = SelectFdr()
X, y = load_breast_cancer(return_X_y=True)
model.fit(X, y)
model_onnx = convert_sklearn(
model, 'select fdr', [('input', Int64TensorType([1, X.shape[1]]))])
self.assertTrue(model_onnx is not None)
dump_data_and_model(
X.astype(np.int64),
model,
model_onnx,
basename="SklearnSelectFdr",
allow_failure=
"StrictVersion(onnx.__version__) < StrictVersion('1.2')")
def select_fdr(input_data,
feature_names=None,
score_func=f_classif,
alpha=0.05):
if score_func == f_classif:
input_data, feature_names, _ = remove_constant(input_data,
feature_names)
x_train = input_data[0]
y_train = input_data[1]
x_test = input_data[2]
y_test = input_data[3]
dims = len(x_train.shape)
if dims == 3:
x_train = flatten(x_train)
x_test = flatten(x_test)
done = False
increment = alpha
while not done:
feature_selector = SelectFdr(score_func=score_func, alpha=alpha)
temp_x_train = feature_selector.fit_transform(x_train, y_train)
temp_x_test = feature_selector.transform(x_test)
if temp_x_train.shape[1] > 1 and temp_x_test.shape[1] > 1:
done = True
x_train = temp_x_train
x_test = temp_x_test
else:
msg = 'Feature selection was too aggresive, '
msg += 'increasing alpha from {} to {}'.format(
alpha, alpha + increment)
alpha += increment
logging.warning(msg)
if dims == 3:
x_train = make3D(x_train)
x_test = make3D(x_test)
output_data = (x_train, y_train, x_test, y_test)
if feature_names is not None:
mask = feature_selector.get_support()
feature_names = feature_names[mask]
logging.info('Selected {} features'.format(x_train.shape[1]))
final_args = {'score_func': score_func, 'alpha': alpha}
return output_data, feature_names, final_args
def SelectComorbidTraits(self,FDR,modifyDataset=False,useChi2=True):
"""
Selects features (symptoms) correlated with some dichotomous variable (disease diagnosis), hence co-morbid. This dichotomous variable is automatically inferred from ClinicalDatasetSampler, as it is whatever the sampler is conditioned on.
Parameters
----------
FDR : float
False discovery rate cut off for feature selection
modifyDataset : bool
If True, then features that faile to be selected will be dropped from the dataset.
useChi2 : bool
By default, uses chi-sq test to estimate co-morbidity between featureVector and features. If False, then Fisher's exact test is used.
Returns
-------
tuple of arrays
(Index of selected features, Feature Scores ,Feature P-values)
"""
assert self.sampler.isConditioned==True,"Cannot perform feature selection without being conditioned on some disease of interest"
previousArrayType = self.sampler.returnArrays
if self.sampler.returnArrays!='Sparse':
self.sampler.ChangeArrayType('Sparse')
sparseTrainingData=self.sampler.ReturnFullTrainingDataset(randomize=False)
dataMatrix=sparseTrainingData[0]
incidenceVec =sparseTrainingData[2]
if useChi2==False:
fdr=SelectFdr(fisher_exact, alpha=FDR)
else:
fdr=SelectFdr(chi2, alpha=FDR)
fdr_fit = fdr.fit(dataMatrix,incidenceVec.toarray())
discIndx=np.where(fdr_fit.get_support()==True)[0]
if modifyDataset:
self.sampler.currentClinicalDataset.IncludeOnly([self.sampler.currentClinicalDataset.dataIndexToDxCodeMap[x] for x in discIndx])
if previousArrayType!='Sparse':
self.sampler.ChangeArrayType(previousArrayType)
return discIndx, fdr_fit.scores_[discIndx],fdr_fit.pvalues_[discIndx]
def select_fdr(df, target_col):
y = df[target_col]
X = df.drop(target_col, axis=1)
selector = SelectFdr(chi2, alpha=0.01).fit(X, y)
true_list = list(selector.get_support())
index = [i for i in range(len(true_list)) if true_list[i] == True]
if len(index) == 0:
print(
'No features were selected: either the data is too noisy or the selection Test_data too strict.'
)
return df
else:
saved_columns = [list(X.columns)[i] for i in index]
result = pd.DataFrame(selector.transform(X), columns=saved_columns)
result[target_col] = y
return result
def build_trained_model(training_data, classifier='svc'):
alpha = [1e-5, 1e-4, 1e-3, 1e-2, 1e-1, 1, 10]
ridge_params = {'alpha': alpha}
c_s = [0.01, 0.1, 1.0, 10.0, 100.0]
gamma = [1e-4, 1e-3, 1e-2, 1e-1, 1, 10]
svc_params = [{
'kernel': ['rbf'],
'gamma': gamma,
'C': c_s
}, {
'kernel': ['linear'],
'C': c_s
}]
if classifier == 'svc':
clf = GridSearchCV(SVC(probability=True), svc_params, cv=5)
# clf = GridSearchCV(SVC(probability=True, class_weight='balanced'), svc_params, cv=5)
elif classifier == 'ridge':
clf = GridSearchCV(RidgeClassifier(), ridge_params, cv=5)
else:
raise NotImplementedError(
"Only 'svc' (default) and 'ridge' classifiers are supported")
pipe = Pipeline([('standard_scalar', StandardScaler()),
('feature_selection', SelectFdr()),
('classification', clf)])
with warnings.catch_warnings():
warnings.simplefilter('ignore')
pipe.fit(training_data.ix[:, :-3], training_data.ix[:,
-3].astype('int'))
return pipe
def test_select_fdr_regression():
"""
Test whether the relative univariate feature selection
gets the correct items in a simple regression problem
with the fdr heuristic
"""
X, Y = make_regression(n_samples=200, n_features=20, n_informative=5, shuffle=False, random_state=0)
univariate_filter = SelectFdr(f_regression, alpha=0.01)
X_r = univariate_filter.fit(X, Y).transform(X)
X_r2 = GenericUnivariateSelect(f_regression, mode="fdr", param=0.01).fit(X, Y).transform(X)
assert_array_equal(X_r, X_r2)
support = univariate_filter.get_support()
gtruth = np.zeros(20)
gtruth[:5] = 1
assert_array_equal(support, gtruth)
def test_select_fdr_float(self):
model = SelectFdr()
X, y = load_breast_cancer(return_X_y=True)
model.fit(X, y)
model_onnx = convert_sklearn(
model, "select fdr", [("input", FloatTensorType([1, X.shape[1]]))])
self.assertTrue(model_onnx is not None)
dump_data_and_model(
X.astype(np.float32),
model,
model_onnx,
basename="SklearnSelectFdr",
allow_failure="StrictVersion(onnx.__version__)"
" < StrictVersion('1.2') or "
"StrictVersion(onnxruntime.__version__)"
" <= StrictVersion('0.2.1')",
)
def SelectComorbidTraits_ContinuousFeature(self,featureVector,FDR,modifyDataset=False,use_ttest=False):
"""
Selects features correlated with some continuous variable.
Parameters
----------
featureVector : [float]
Vector of floating values for feature selection. Must be sorted in the same order as the index for the ClinicalDatasetSampler training dataset.
FDR : float
False discovery rate cut off for feature selection
modifyDataset : bool
If True, then features that faile to be selected will be dropped from the dataset.
use_ttest : bool
By default, uses F-test to estimate correlation between featureVector and features. If True, instead uses T-test to perform association.
Returns
-------
tuple of arrays
(Index of selected features, Feature Scores ,Feature P-values)
"""
previousArrayType = self.sampler.returnArrays
if self.sampler.returnArrays!='Sparse':
self.sampler.ChangeArrayType('Sparse')
sparseTrainingData=self.sampler.ReturnFullTrainingDataset(randomize=False)
dataMatrix=sparseTrainingData[0]
if use_ttest:
fdr=SelectFdr(T_test, alpha=FDR)
else:
fdr=SelectFdr(f_regression, alpha=FDR)
fdr_fit = fdr.fit(dataMatrix,featureVector.ravel())
discIndx=np.where(fdr_fit.get_support()==True)[0]
if modifyDataset:
self.sampler.currentClinicalDataset.IncludeOnly([self.sampler.currentClinicalDataset.dataIndexToDxCodeMap[x] for x in discIndx])
if previousArrayType!='Sparse':
self.sampler.ChangeArrayType(previousArrayType)
return discIndx, fdr_fit.scores_[discIndx],fdr_fit.pvalues_[discIndx]
def test_verbose_output_for_select_select_fdr():
expected_output = ("The p-value of column 'B' (1.0000) is above the " +
"specified alpha of 0.5000")
model = SelectFdr(chi2, alpha=0.5)
output = _capture_verbose_output_for_model(model, use_supervised_df=True)
assert output == expected_output
def featureFitting( filename, X, y, featureNames,optimalFlag, kbest=20, alpha=0.05,model=None):
'''
Gets the K-best features (filtered by FDR, then select best ranked by t-test , more advanced options can be implemented).
Save the data/matrix with the resulting/kept features to a new output file, "REDUCED_Feat.csv"
'''
a=alpha
FD = SelectFdr(alpha=a)
X = FD.fit_transform(X,y)
selectK = SelectKBest(k=kbest)
selectK.fit(X,y)
selectK_mask=selectK.get_support()
K_featnames = featureNames[selectK_mask]
print("K_featnames: %s" %(K_featnames))
Reduced_df = pd.read_csv(filename, index_col=0)
Reduced_df = Reduced_df[Reduced_df.columns[selectK_mask]]
Reduced_df.to_csv('REDUCED_Feat.csv')
return Reduced_df
def test_select_fdr_regression():
"""
Test whether the relative univariate feature selection
gets the correct items in a simple regression problem
with the fdr heuristic
"""
X, y = make_regression(n_samples=200, n_features=20,
n_informative=5, shuffle=False, random_state=0)
univariate_filter = SelectFdr(f_regression, alpha=0.01)
X_r = univariate_filter.fit(X, y).transform(X)
X_r2 = GenericUnivariateSelect(f_regression, mode='fdr',
param=0.01).fit(X, y).transform(X)
assert_array_equal(X_r, X_r2)
support = univariate_filter.get_support()
gtruth = np.zeros(20)
gtruth[:5] = 1
assert_array_equal(support, gtruth)
def selectFdr(args):
"""Uses scikit-learn's SelectFdr, select the p-values for an estimated false discovery rate.
Parameters
----------
score_func : callable
Function taking two arrays X and y, and returning a pair of arrays (scores, pvalues).
alpha : float, optional
The highest uncorrected p-value for features to keep.
"""
if (args[2] == "chi2"):
selector = SelectFdr(chi2, alpha=float(args[1]))
elif (args[2] == "f_classif"):
selector = SelectFdr(f_classif, alpha=float(args[1]))
return selector
def build_trained_model(training_data):
pipe = Pipeline([('scaler', StandardScaler()),
('feature_selection', SelectFdr()),
('classification', SVC(probability=True))])
with warnings.catch_warnings():
warnings.simplefilter('ignore')
pipe.fit(training_data.ix[:, :-3], training_data.ix[:,
-3].astype('int'))
return pipe
def select_fdr(args):
# https://scikit-learn.org/stable/modules/generated/sklearn.feature_selection.SelectFdr.html
from sklearn.feature_selection import f_classif, chi2
if args['alpha'] is None:
args['alpha'] = 0.05
if args['score_function'] == 'chi2':
args['score_function'] = chi2
elif args['score_function'] == 'f_classif':
args['score_function'] = f_classif
return SelectFdr(score_func=args['score_function'], alpha=args['alpha'])
def test_pipeline_shares_structure():
pipeline = dl.Pipeline([("scale", StandardScaler()), ("fdr", SelectFdr()),
("svm", LinearSVC())])
pipeline1 = pipeline.fit(X, y)
score1 = pipeline1.score(X, y)
pipeline2 = pipeline.set_params(svm__C=0.1)
pipeline2 = pipeline2.fit(X, y)
score2 = pipeline2.score(X, y)
assert (len(merge(score1.dask, score2.dask)) <=
(len(score1.dask) + len(score2.dask)) * 0.75)
assert score1.key != score2.key
def feature_selection(df,tgt,mtd,slct=10): '''function to do feature selection for the target specified by tgt and using the method specified by mtd''' target = df[tgt] features = df.drop([tgt], axis=1) if mtd == 'KBest': bestfeatures = SelectKBest(score_func=f_classif, k=slct) fit = bestfeatures.fit(features,target) dfscores = pd.DataFrame(fit.scores_) dfcolumns = pd.DataFrame(features.columns) #dfpvalues = pd.DataFrame(fit.pvalues_) #not providing useful insight featureScores = pd.concat([dfcolumns,dfscores],axis=1) featureScores.columns = ['Features','Score'] #naming the dataframe columns featureScores = featureScores.sort_values(by=['Score'],ascending=False) #sort to see most important features at the top select_cols = features.columns.values[fit.get_support()] #get_support returns a boolean vector indicating which features (columns' names) were selected selectfeatures = pd.DataFrame(fit.transform(features),columns = select_cols) #build dataframe with selected features only elif mtd == 'Fdr': bestfeatures = SelectFdr(score_func=f_classif, alpha=0.05) fit = bestfeatures.fit(features,target) dfscores = pd.DataFrame(fit.scores_) dfcolumns = pd.DataFrame(features.columns) #dfpvalues = pd.DataFrame(fit.pvalues_) #not providing useful insight featureScores = pd.concat([dfcolumns,dfscores],axis=1) featureScores.columns = ['Features','Score'] #naming the dataframe columns featureScores = featureScores.sort_values(by=['Score'],ascending=False) #sort to see most important features at the top select_cols = features.columns.values[fit.get_support()] #get_support returns a boolean vector indicating which features (columns' names) were selected selectfeatures = pd.DataFrame(fit.transform(features),columns = select_cols) #build dataframe with selected features only elif mtd == 'Fwe': bestfeatures = SelectFwe(score_func=f_classif, alpha=0.05) fit = bestfeatures.fit(features,target) dfscores = pd.DataFrame(fit.scores_) dfcolumns = pd.DataFrame(features.columns) #dfpvalues = pd.DataFrame(fit.pvalues_) #not providing useful insight featureScores = pd.concat([dfcolumns,dfscores],axis=1) featureScores.columns = ['Features','Score'] #naming the dataframe columns featureScores = featureScores.sort_values(by=['Score'],ascending=False) #sort to see most important features at the top select_cols = features.columns.values[fit.get_support()] #get_support returns a boolean vector indicating which features (columns' names) were selected selectfeatures = pd.DataFrame(fit.transform(features),columns = select_cols) #build dataframe with selected features only elif mtd == 'Pct': bestfeatures = SelectPercentile(score_func=f_classif, percentile=20) fit = bestfeatures.fit(features,target) dfscores = pd.DataFrame(fit.scores_) dfcolumns = pd.DataFrame(features.columns) #dfpvalues = pd.DataFrame(fit.pvalues_) #not providing useful insight featureScores = pd.concat([dfcolumns,dfscores],axis=1) featureScores.columns = ['Features','Score'] #naming the dataframe columns featureScores = featureScores.sort_values(by=['Score'],ascending=False) #sort to see most important features at the top select_cols = features.columns.values[fit.get_support()] #get_support returns a boolean vector indicating which features (columns' names) were selected selectfeatures = pd.DataFrame(fit.transform(features),columns = select_cols) #build dataframe with selected features only return select_cols #selectfeatures featureScores
def get_fsmethod (fsmethod, n_feats, n_subjs, n_jobs=1):
if fsmethod == 'stats':
return 'stats', None
#Feature selection procedures
#http://scikit-learn.org/stable/modules/generated/sklearn.feature_selection.RFE.html
fsmethods = { 'rfe' : RFE(estimator=SVC(kernel="linear"), step=0.05, n_features_to_select=2),
#http://scikit-learn.org/stable/modules/generated/sklearn.feature_selection.RFE.html
'rfecv' : RFECV(estimator=SVC(kernel="linear"), step=0.05, loss_func=zero_one), #cv=3, default; cv=StratifiedKFold(n_subjs, 3)
#Univariate Feature selection: http://scikit-learn.org/stable/modules/generated/sklearn.feature_selection.SelectPercentile.html
'univariate': SelectPercentile(f_classif, percentile=5),
#http://scikit-learn.org/stable/modules/generated/sklearn.feature_selection.SelectFpr.html
'fpr' : SelectFpr (f_classif, alpha=0.05),
#http://scikit-learn.org/stable/modules/generated/sklearn.feature_selection.SelectFdr.html
'fdr' : SelectFdr (f_classif, alpha=0.05),
#http://scikit-learn.org/stable/modules/feature_selection.html
'extratrees': ExtraTreesClassifier(n_estimators=50, max_features='auto', compute_importances=True, n_jobs=n_jobs, random_state=0),
'pca' : PCA(n_components='mle'),
'rpca' : RandomizedPCA(random_state=0),
'lda' : LDA(),
}
#feature selection parameter values for grid search
max_feats = ['auto']
if n_feats < 10:
feats_to_sel = range(2, n_feats, 2)
n_comps = range(1, n_feats, 2)
else:
feats_to_sel = range(2, 20, 4)
n_comps = range(1, 30, 4)
max_feats.extend(feats_to_sel)
n_comps_pca = list(n_comps)
n_comps_pca.extend(['mle'])
fsgrid = { 'rfe' : dict(estimator_params = [dict(C=0.1), dict(C=1), dict(C=10)], n_features_to_select = feats_to_sel),
'rfecv' : dict(estimator_params = [dict(C=0.1), dict(C=1), dict(C=10)]),
'univariate': dict(percentile = [1, 3, 5, 10]),
'fpr' : dict(alpha = [1, 3, 5, 10]),
'fdr' : dict(alpha = [1, 3, 5, 10]),
'extratrees': dict(n_estimators = [1, 3, 5, 10, 30, 50], max_features = max_feats),
'pca' : dict(n_components = n_comps_pca, whiten = [True, False]),
'rpca' : dict(n_components = n_comps, iterated_power = [3, 4, 5], whiten = [True, False]),
'lda' : dict(n_components = n_comps)
}
return fsmethods[fsmethod], fsgrid[fsmethod]
def select_features(data,
features,
target,
feature_selector='SelectKBest',
k=10,
alpha=0.05,
score_func='f_classif'):
X = data[features]
y = data[target]
if score_func == 'f_classif':
score_func = f_classif
elif score_func == 'f_regression':
score_func = f_regression
elif score_func == 'chi2':
score_func = chi2
elif score_func == 'mutual_info_classif':
score_func = mutual_info_classif
elif score_func == 'mutual_info_regression':
score_func = mutual_info_regression
else:
raise Exception('Undefined score_func')
if feature_selector == 'SelectKBest':
feature_selector = SelectKBest(score_func=score_func, k=k)
elif feature_selector == 'SelectFpr':
feature_selector = SelectFpr(score_func=score_func, alpha=alpha)
elif feature_selector == 'SelectFdr':
feature_selector = SelectFdr(score_func=score_func, alpha=alpha)
else:
raise Exception('Undefined score_func')
feature_selector.fit_transform(X, y)
feature_index = [
zero_based_index
for zero_based_index in list(feature_selector.get_support(
indices=True))
]
best_features = []
for i in feature_index:
best_features.append(features[i])
print('Best features selected are: ' + str(best_features))
return best_features
def test_no_feature_selected():
rng = np.random.RandomState(0)
# Generate random uncorrelated data: a strict univariate test should
# rejects all the features
X = rng.rand(40, 10)
y = rng.randint(0, 4, size=40)
strict_selectors = [
SelectFwe(alpha=0.01).fit(X, y),
SelectFdr(alpha=0.01).fit(X, y),
SelectFpr(alpha=0.01).fit(X, y),
SelectPercentile(percentile=0).fit(X, y),
SelectKBest(k=0).fit(X, y),
]
for selector in strict_selectors:
assert_array_equal(selector.get_support(), np.zeros(10))
X_selected = assert_warns_message(
UserWarning, 'No features were selected', selector.transform, X)
assert_equal(X_selected.shape, (40, 0))
def feature_sel(x,
y,
sel_method='estimator',
k=None,
estimator=None,
score_func=chi2):
"""
:param x:
:param y:
:param k:
:param sel_method: kbest, fdr, fpr, fwe, estimator, rfecv
:param estimator:
:param score_func:
:return:
"""
if sel_method == 'kbest':
assert k is not None
selector = SelectKBest(score_func, k)
elif sel_method == 'fdr':
selector = SelectFdr(score_func, alpha=0.05)
elif sel_method == 'fpr':
selector = SelectFpr(score_func, alpha=0.05)
elif sel_method == 'fwe':
selector = SelectFwe(score_func, alpha=0.05)
elif sel_method == 'estimator':
assert estimator is not None
if k is None:
selector = SelectFromModel(estimator=estimator)
else:
selector = SelectFromModel(estimator=estimator,
max_features=k,
threshold=-np.inf)
elif sel_method == 'rfecv':
assert estimator is not None
selector = RFECV(estimator, step=1, cv=5)
else:
raise Exception('unknown input parameters.')
assert selector is not None
x_new = selector.fit_transform(x, y)
return selector.get_support(), x_new, y
def svm_cv(data, data_target):
X_train, X_test, y_train, y_test = cross_validation.train_test_split(data, data_target)
print "*" * 79
print "Training..."
# selector = SelectFdr(chi2)
selector = SelectFdr(f_classif)
selector.fit(X_train, y_train)
clf = svm.SVC(kernel='linear', probability=True)
clf.fit(selector.transform(X_train), y_train)
print "Testing..."
pred = clf.predict(selector.transform(X_test))
probs = pred.predict_proba(selector.transfrom(X_test))
accuracy_score = metrics.accuracy_score(y_test, pred)
classification_report = metrics.classification_report(y_test, pred)
support = selector.get_support()
print support
print accuracy_score
print classification_report
precision, recall, thresholds = precision_recall_curve(y_test, probs[:, 1])
Kcv=4 #Number of stratified folds for cross validation. More = slower, more accurate.
fileName = r'\trainingSetFeatures.csv'
# filePath = r'E:\Dropbox\Dropbox\BioInformatics Lab\AA_Information\CODE\Feature_Extract\test_seq\Chap'
filePath = str(input('Input DIRRectory containing TrainingData csv '))
## features, labels, lb_encoder,featureNames = load_data(filename, 'file')
features, labels, lb_encoder,featureNames = load_data(filePath+fileName, 'file')
X, y = features, labels
print('len(set(y)',len(set(y)))
print(X.shape,"X = samples, features")
scale = StandardScaler(copy=False)
X = scale.fit_transform(X)
FD = SelectFdr(alpha=0.0005)
FD_K = SelectPercentile(percentile=70)
X = FD.fit_transform(X,y)
print(X.shape,"X post FDR alpha filter")
X_FD = FD_K.fit_transform(X,y)
print(X_FD.shape,"X post FDR+K-best alpha filter")
print("\n BASE X models: \n")
ModelParam_GridSearch(X,y,cv=Kcv)
'''
pca = PCA(n_components='mle')
X_PCA = pca.fit_transform(X)
print(X_PCA.shape,"X - PCA,mle")
ModelParam_GridSearch(X_PCA,y,cv=Kcv)
'''