def compute_imp_score(model, metric, training_features, training_classes,
random_state):
"""compute importance scores for features.
If coef_ or feature_importances_ attribute is available for the model,
the the importance scores will be based on the attribute. If not,
then permuation importance scores will be estimated
Parameters
----------
tmpdir: string
Temporary directory for saving experiment results
model: scikit-learn Estimator
A fitted scikit-learn model
metric: str, callable
The metric for evaluating the feature importance through
permutation. By default, the strings 'accuracy' is
recommended for classifiers and the string 'r2' is
recommended for regressors. Optionally, a custom
scoring function (e.g., `metric=scoring_func`) that
accepts two arguments, y_true and y_pred, which have
similar shape to the `y` array.
training_features: np.darray/pd.DataFrame
Features in training dataset
training_classes: np.darray/pd.DataFrame
Target in training dataset
random_state: int
Random seed for permuation importances
Returns
-------
coefs: np.darray
Feature importance scores
imp_score_type: string
Importance score type
"""
# exporting/computing importance score
if hasattr(model, 'coef_'):
coefs = model.coef_
if coefs.ndim > 1:
coefs = safe_sqr(coefs).sum(axis=0)
imp_score_type = "Sum of Squares of Coefficients"
else:
coefs = safe_sqr(coefs)
imp_score_type = "Squares of Coefficients"
else:
coefs = getattr(model, 'feature_importances_', None)
imp_score_type = "Gini Importance"
if coefs is None or np.isnan(coefs).any():
coefs, _ = feature_importance_permutation(
predict_method=model.predict,
X=training_features,
y=training_classes,
num_rounds=5,
metric=metric,
seed=random_state,
)
imp_score_type = "Permutation Feature Importance"
return coefs, imp_score_type
def if_classif(X_y, n_features):
"""Compute the Anova F-value for the provided sample
Parameters
----------
X_y : Tuples of (X, y) with
X {array-like, sparse matrix} shape = [n_samples, n_features]
The set of regressors that will tested sequentially
y array of shape(n_samples)
The data matrix
Returns
-------
F : array, shape = [n_features,]
The set of F values
pval : array, shape = [n_features,]
The set of p-values
"""
n_samples = 0
n_samples_per_class = defaultdict(lambda: 0)
sums_args_d = defaultdict(lambda: np.zeros(shape=(n_features)))
ss_alldata = np.zeros(shape=(n_features))
for X, y in X_y:
if(n_samples % 100) == 0:
logger.info("Processing doc #%d..." % n_samples)
n_samples += 1
n_samples_per_class[y] += 1
ss_alldata[:] += X[:]**2
sums_args_d[y][:] += X[:]
n_classes = len(sums_args_d.keys())
#Convert dictionary to numpy array
sums_args = np.array(list(row for row in sums_args_d.itervalues()))
square_of_sums_alldata = safe_sqr(reduce(lambda x, y: x + y, sums_args))
square_of_sums_args = [safe_sqr(s) for s in sums_args]
sstot = ss_alldata - square_of_sums_alldata / float(n_samples)
ssbn = 0.
for k, y in enumerate(n_samples_per_class.keys()):
ssbn += square_of_sums_args[k] / n_samples_per_class[y]
ssbn -= square_of_sums_alldata / float(n_samples)
sswn = sstot - ssbn
dfbn = n_classes - 1
dfwn = n_samples - n_classes
msb = ssbn / float(dfbn)
msw = sswn / float(dfwn)
f = msb / msw
# flatten matrix to vector in sparse case
f = np.asarray(f).ravel()
prob = stats.fprob(dfbn, dfwn, f)
return f, prob
def f_regression_cov(X, y, C):
"""Univariate linear regression tests
Quick linear model for testing the effect of a single regressor,
sequentially for many regressors.
This is done in 3 steps:
1. the regressor of interest and the data are orthogonalized
wrt constant regressors
2. the cross correlation between data and regressors is computed
3. it is converted to an F score then to a p-value
Parameters
----------
X : {array-like, sparse matrix} shape = (n_samples, n_features)
The set of regressors that will tested sequentially.
y : array of shape(n_samples).
The data matrix
c : {array-like, sparse matrix} shape = (n_samples, n_covariates)
The set of covariates.
Returns
-------
F : array, shape=(n_features,)
F values of features.
pval : array, shape=(n_features,)
p-values of F-scores.
"""
X = check_array(X, dtype=np.float)
C = check_array(C, dtype=np.float)
y = check_array(y, dtype=np.float)
y = y.ravel()
assert C.shape[1] < C.shape[0]
cpinv = np.linalg.pinv(C)
X -= np.dot(C, (np.dot(cpinv, X)))
y -= np.dot(C, (np.dot(cpinv, y)))
# compute the correlation
corr = np.dot(y, X)
corr /= np.asarray(np.sqrt(safe_sqr(X).sum(axis=0))).ravel()
corr /= np.asarray(np.sqrt(safe_sqr(y).sum())).ravel()
# convert to p-value
dof = (X.shape[0] - 1 - C.shape[1]) / (1) #(df_fm / (df_rm - df_fm))
F = corr**2 / (1 - corr**2) * dof
pv = stats.f.sf(F, 1, dof)
return F, pv
def f_regression_cov(X, y, C):
"""Univariate linear regression tests
Quick linear model for testing the effect of a single regressor,
sequentially for many regressors.
This is done in 3 steps:
1. the regressor of interest and the data are orthogonalized
wrt constant regressors
2. the cross correlation between data and regressors is computed
3. it is converted to an F score then to a p-value
Parameters
----------
X : {array-like, sparse matrix} shape = (n_samples, n_features)
The set of regressors that will tested sequentially.
y : array of shape(n_samples).
The data matrix
c : {array-like, sparse matrix} shape = (n_samples, n_covariates)
The set of covariates.
Returns
-------
F : array, shape=(n_features,)
F values of features.
pval : array, shape=(n_features,)
p-values of F-scores.
"""
X = check_arrays(X, dtype=np.float)
C = check_arrays(C, dtype=np.float)
y = check_arrays(y, dtype=np.float)
y = y.ravel()
assert C.shape[1] < C.shape[0]
cpinv = np.linalg.pinv(C)
X -= np.dot(C,(np.dot(cpinv, X)))
y -= np.dot(C,(np.dot(cpinv, y)))
# compute the correlation
corr = np.dot(y, X)
corr /= np.asarray(np.sqrt(safe_sqr(X).sum(axis=0))).ravel()
corr /= np.asarray(np.sqrt(safe_sqr(y).sum())).ravel()
# convert to p-value
dof = (X.shape[0] - 1 - C.shape[1]) / (1) #(df_fm / (df_rm - df_fm))
F = corr ** 2 / (1 - corr ** 2) * dof
pv = stats.f.sf(F, 1, dof)
return F, pv
def f_oneway(*args):
n_classes = len(args)
args = [as_float_array(a) for a in args]
n_samples_per_class = np.array([a.shape[0] for a in args])
n_samples = np.sum(n_samples_per_class)
ss_alldata = sum(safe_sqr(a).sum(axis=0) for a in args)
sums_args = [np.asarray(a.sum(axis=0)) for a in args]
square_of_sums_alldata = sum(sums_args)**2
square_of_sums_args = [s**2 for s in sums_args]
sstot = ss_alldata - square_of_sums_alldata / float(n_samples)
ssbn = 0.
for k, _ in enumerate(args):
ssbn += square_of_sums_args[k] / n_samples_per_class[k]
ssbn -= square_of_sums_alldata / float(n_samples)
sswn = sstot - ssbn
dfbn = n_classes - 1
dfwn = n_samples - n_classes
msb = ssbn / float(dfbn)
msw = sswn / float(dfwn)
constant_features_idx = np.where(msw == 0.)[0]
if (np.nonzero(msb)[0].size != msb.size and constant_features_idx.size):
warnings.warn("Features %s are constant." % constant_features_idx,
UserWarning)
f = msb / msw
# flatten matrix to vector in sparse case
f = np.asarray(f).ravel()
prob = special.fdtrc(dfbn, dfwn, f)
return f, prob
def read_selected_features_from_pipeline(classification_pipeline, is_sorted=True):
"""
Given a classification pipeline, sort all of the features
from the 'selector', as well as return the selection
of features
Arguments:
classification_pipeline
"""
rfe_step = classification_pipeline.named_steps.selection.named_steps.rfe
# Get selected features
sorted_idxs = np.argsort(safe_sqr(rfe_step.estimator_.coef_).sum(axis=0))
mask = rfe_step.support_
selected_features = np.array(read_all_features_from_pipeline(classification_pipeline))[mask]
if not is_sorted:
return selected_features
# Sort selected features from bottom (worst) to highest (best)
return selected_features[sorted_idxs]
def _fit(self, X, y, features_names=None, preload_features=None,
ranking_th=0.005):
X, y = check_X_y(X, y, accept_sparse=['csr', 'csc', 'coo'],
multi_output=True)
# Initialization
n_features = X.shape[1]
features = np.arange(n_features)
cv = self.cv
cv = check_cv(cv, y, classifier=is_classifier(self.estimator))
if sklearn.__version__ == '0.17':
n_splits = cv.n_folds
else:
n_splits = cv.get_n_splits(X, y)
if self.verbose > 0:
print("Fitting {0} folds for each of iteration".format(n_splits))
if 0.0 < self.n_features_step < 1.0:
step = int(max(1, self.n_features_step * n_features))
else:
step = int(self.n_features_step)
if step <= 0:
raise ValueError("Step must be >0")
if features_names is not None:
features_names = np.array(features_names)
else:
if self.features_names is not None:
features_names = self.features_names
else:
features_names = np.arange(n_features) # use indices
tentative_support_ = np.zeros(n_features, dtype=np.bool)
current_support_ = np.zeros(n_features, dtype=np.bool)
self.scores_ = []
self.scores_confidences_ = []
self.features_per_it_ = []
if preload_features is not None:
preload_features = np.unique(preload_features).astype('int')
current_support_[preload_features] = True
X_selected = X[:, features[current_support_]]
y_hat, cv_scores = my_cross_val_predict(clone(self.estimator),
X_selected, y, cv=cv)
target = y - y_hat
else:
target = y.copy()
score, confidence_interval = -np.inf, 0
proceed = np.sum(current_support_) < X.shape[1]
while proceed:
if self.verbose > 0:
print('\nN-times variance of target: {}'.format(
target.var() * target.shape[0]))
# update values
old_confidence_interval = confidence_interval
old_score = score
if self.scale:
target = StandardScaler().fit_transform(target.reshape(
-1, 1)).ravel()
# target = MinMaxScaler().fit_transform(target.reshape(
# -1,1)).ravel()
if self.verbose > 0:
print()
print('Feature ranking')
print()
print("target shape: {}".format(target.shape))
print()
# Rank the remaining features
start_t = time.time()
rank_estimator = clone(self.estimator)
rank_estimator.fit(X, target)
end_fit = time.time() - start_t
# Get coefs
start_t = time.time()
if hasattr(rank_estimator, 'coef_'):
coefs = rank_estimator.coef_
elif hasattr(rank_estimator, 'feature_importances_'):
coefs = rank_estimator.feature_importances_
else:
raise RuntimeError('The classifier does not expose '
'"coef_" or "feature_importances_" '
'attributes')
end_rank = time.time() - start_t
# Get ranks by ordering in ascending way
if coefs.ndim > 1:
ranks = np.argsort(safe_sqr(coefs).sum(axis=0))
coefs = coefs.sum(axis=0)
else:
ranks = np.argsort(safe_sqr(coefs))
# for sparse case ranks is matrix
ranks = np.ravel(ranks)
if self.verbose > 0:
ranked_f = features[ranks]
if features_names is not None:
ranked_n = features_names[ranks]
else:
ranked_n = ['-'] * n_features
print('{:6}\t{:6}\t{:8}\t{}'.format('Rank', 'Index', 'Score',
'Feature Name'))
for i in range(n_features):
idx = n_features - i - 1
if (coefs[ranks[idx]] < ranking_th) and (i > 2):
print(' ...')
break
print('#{:6}\t{:6}\t{:6f}\t{}'.format(str(i),
str(ranked_f[idx]),
coefs[ranks[idx]],
ranked_n[idx]))
print(
"\n Fit done in {} s and rank done in {} s".format(end_fit,
end_rank))
# if coefs[ranks][-1] < 1e-5:
# if self.verbose > 0:
# import warnings
# warnings.warn('scores are too small to be used, please standardize inputs')
# break
# get the best features (ie, the latest one)
# if the most ranked features is selected go on a select
# other features accordingly to the ranking
# threshold = step
# step_features = features[ranks][-threshold:]
ii = len(features_names) - 1
step_features = features[ranks][ii]
while np.all(current_support_[step_features]) and ii > 0:
ii -= 1
step_features = features[ranks][ii]
if np.all(current_support_[step_features]):
if self.verbose > 0:
print("Selected features: {} {}".format(
features_names[step_features], step_features))
# if features_names is not None:
# print("Selected features: {} {}".format(features_names[ranks][-threshold:], step_features))
# else:
# print("Selected features: {}".format(step_features))
print('Ended because selected features already selected')
step_features = None
break
# update selected features
tentative_support_[step_features] = True
# get the selected features
X_selected = X[:, features[tentative_support_]]
start_t = time.time()
# cross validates to obtain the scores
y_hat, cv_scores = my_cross_val_predict(clone(self.estimator),
X_selected, y, cv=cv)
# y_hat = cross_val_predict(clone(self.estimator), X_selected, y, cv=cv)
# compute new target
target = y - y_hat
# compute score and confidence interval
# score = r2_score(y_true=y, y_pred=y_hat, multioutput='uniform_average') # np.mean(cv_scores)
if self.verbose > 0:
print('r2: {}'.format(np.mean(cv_scores, axis=0)))
score = np.mean(cv_scores)
if len(cv_scores.shape) > 1:
cv_scores = np.mean(cv_scores, axis=1)
m2 = np.mean(cv_scores * cv_scores)
confidence_interval_or = np.sqrt(
(m2 - score * score) / (n_splits - 1))
end_t = time.time() - start_t
if self.verbose > 0:
# if features_names is not None:
print("Selected features: {} {}".format(
features_names[step_features], step_features))
print("Total features: {} {}".format(
features_names[tentative_support_],
features[tentative_support_]))
# else:
# print("Selected features: {}".format(step_features))
# print("Total features: {}".format(features[tentative_support_]))
print("R2= {} +- {}".format(score, confidence_interval_or))
print("\nCrossvalidation done in {} s".format(end_t))
confidence_interval = confidence_interval_or * self.significance # do not trust confidence interval completely
# check terminal condition
proceed = score - old_score > old_confidence_interval + confidence_interval
if self.verbose > 0:
print("PROCEED: {}\n\t{} - {} > {} + {}\n\t{} > {} )".format(
proceed, score, old_score,
old_confidence_interval,
confidence_interval,
score - old_score,
old_confidence_interval + confidence_interval))
if proceed or np.sum(current_support_) == 0:
# last feature set proved to be informative
# we need to take into account of the new features (update current support)
current_support_[step_features] = True
self.features_per_it_.append(features_names[step_features])
self.scores_.append(score)
self.scores_confidences_.append(confidence_interval)
# all the features are selected, stop
if np.sum(current_support_) == n_features:
if self.verbose > 0:
print("All the features has been selected.")
proceed = False
else:
# last feature set proved to be not informative
# keep old support and delete the current one (it is no more necessary)
del tentative_support_
if self.verbose > 0:
print('Last feature {} not added to the set'.format(
features_names[step_features]))
# Set final attributes
self.estimator_ = clone(self.estimator)
# self.estimator_.fit(Xns[:, current_support_], yns)
self.estimator_.fit(X[:, current_support_], y)
self.n_features_ = current_support_.sum()
self.support_ = current_support_
# self.ranking_ = ranking_
return self
def f_regression_cov_alt(X, y, C):
"""
Implementation as derived in tex document
See pg 12 of following document for definition of F-statistic
http://www-stat.stanford.edu/~jtaylo/courses/stats191/notes/simple_diagnostics.pdf
Parameters
----------
X : {array-like, sparse matrix} shape = (n_samples, n_features)
The set of regressors that will tested sequentially.
y : array of shape(n_samples).
The data matrix
c : {array-like, sparse matrix} shape = (n_samples, n_covariates)
The set of covariates.
Returns
-------
F : array, shape=(n_features,)
F values of features.
pval : array, shape=(n_features,)
p-values of F-scores.
"""
# make sure we don't overwrite input data
old_flag_X = X.flags.writeable
old_flag_C = C.flags.writeable
old_flag_y = y.flags.writeable
X.flags.writeable = False
C.flags.writeable = False
y.flags.writeable = False
#X, C, y = check_arrays(X, C, y, dtype=np.float)
y = y.ravel()
# make copy of input data
X = X.copy(order="F")
y = y.copy()
assert C.shape[1] < C.shape[0]
cpinv = np.linalg.pinv(C)
X -= np.dot(C,(np.dot(cpinv, X))) #most expensive line (runtime)
y -= np.dot(C,(np.dot(cpinv, y)))
yS = safe_sqr(y.T.dot(X)) # will create a copy
# Note: (X*X).sum(0) = X.T.dot(X).diagonal(), computed efficiently
# see e.g.: http://stackoverflow.com/questions/14758283/is-there-a-numpy-scipy-dot-product-calculating-only-the-diagonal-entries-of-the
# TODO: make this smarter using either stride tricks or cython
X *= X
denom = X.sum(0) * y.T.dot(y) - yS
F = yS / denom
# degrees of freedom
dof = (X.shape[0] - 1 - C.shape[1]) / (1) #(df_fm / (df_rm - df_fm))
F *= dof
# convert to p-values
pv = stats.f.sf(F, 1, dof)
# restore old state
X.flags.writeable = old_flag_X
C.flags.writeable = old_flag_C
y.flags.writeable = old_flag_y
return F, pv
def _fit(self, X, y, step_score=None):
# Parameter step_score controls the calculation of self.scores_
# step_score is not exposed to users
# and is used when implementing RFACV
# self.scores_ will not be calculated when calling _fit through fit
X, y = check_X_y(X, y, "csc")
# Initialization
n_features = X.shape[1]
if self.n_features_to_select is None:
n_features_to_select = n_features // 2
else:
n_features_to_select = self.n_features_to_select
if 0.0 < self.step < 1.0:
step = int(max(1, self.step * n_features))
else:
step = int(self.step)
if step <= 0:
raise ValueError("Step must be >0")
support_added_ = np.zeros(n_features, dtype=np.bool)
support_ = np.ones(n_features, dtype=np.bool)
ranking_ = np.ones(n_features, dtype=np.int)
ranking_added_ = np.ones(n_features, dtype=np.int)
if step_score:
self.scores_ = []
# Adding
while np.sum(support_) > n_features_to_select:
# Remaining features
features = np.arange(n_features)[support_]
# Added features
features_added = np.arange(n_features)[support_added_]
# Compute step score on the previous added features
if step_score and np.sum(support_added_) > 0:
estimator_added = clone(self.estimator)
estimator_added.fit(X[:, features_added], y)
self.scores_.append(step_score(estimator_added, features_added))
# Rank the remaining features
estimator = clone(self.estimator)
if self.verbose > 0:
print("Fitting estimator with %d features." % np.sum(support_))
estimator.fit(X[:, features], y)
# Get coefs
if hasattr(estimator, 'coef_'):
coefs = estimator.coef_
else:
coefs = getattr(estimator, 'feature_importances_', None)
if coefs is None:
raise RuntimeError('The classifier does not expose '
'"coef_" or "feature_importances_" '
'attributes')
# Get ranks
# ! For RFA, the rank is inverted: (np.argsort(list) replaced by (np.argsort(-list)
if coefs.ndim > 1:
try:
ranks = np.argsort(-safe_sqr(coefs).sum(axis=0))
except ValueError:
coefs = np.nan_to_num(coefs)
ranks = np.argsort(-safe_sqr(coefs).sum(axis=0))
else:
try:
ranks = np.argsort(-safe_sqr(coefs))
except ValueError:
coefs = np.nan_to_num(coefs)
ranks = np.argsort(-safe_sqr(coefs))
# for sparse case ranks is matrix
ranks = np.ravel(ranks)
# Add the best features
threshold = min(step, np.sum(support_) - n_features_to_select)
# remaining features to test
support_[features[ranks][:threshold]] = False
ranking_[np.logical_not(support_)] += 1
# added/ranked features
support_added_[features[ranks][:threshold]] = True
ranking_added_[np.logical_not(support_added_)] += 1
# Set final attributes
features_added = np.arange(n_features)[support_added_]
self.estimator_ = clone(self.estimator)
self.estimator_.fit(X[:, features_added], y)
# Compute step score when only n_features_to_select features left
if step_score:
self.scores_.append(step_score(self.estimator_, features_added))
self.n_features_ = support_added_.sum()
self.support_ = support_added_
self.ranking_ = ranking_added_
return self
def _fit(self, X, y, step_score=None):
X, y = check_X_y(X, y, "csc")
# Initialization
n_features = X.shape[1]
if self.n_features_to_select is None:
n_features_to_select = n_features // 2
else:
n_features_to_select = self.n_features_to_select
if 0.0 < self.step < 1.0:
if not self.stepwise_selection:
step = int(max(1, self.step * n_features))
else:
step = self.step
else:
if self.stepwise_selection:
warnings.warn(
"The parameter 'stepwise_selection' is true but "
"a fixed step size is given. Procedure will "
" continue as if 'stepwise_selection' is false",
RuntimeWarning)
step = int(self.step)
if step <= 0:
raise ValueError("Step must be >0")
if self.estimator_params is not None:
warnings.warn(
"The parameter 'estimator_params' is deprecated as "
"of version 0.16 and will be removed in 0.18. The "
"parameter is no longer necessary because the value "
"is set via the estimator initialisation or "
"set_params method.", DeprecationWarning)
support_ = np.ones(n_features, dtype=np.bool)
ranking_ = np.ones(n_features, dtype=np.int)
if step_score:
self.scores_ = []
# Elimination
while np.sum(support_) > n_features_to_select:
# Remaining features
features = np.arange(n_features)[support_]
# Rank the remaining features
estimator = clone(self.estimator)
if self.estimator_params:
estimator.set_params(**self.estimator_params)
if self.verbose > 0:
print("Fitting estimator with %d features." % np.sum(support_))
estimator.fit(X[:, features], y)
# Get coefs
if hasattr(estimator, 'coef_'):
coefs = estimator.coef_
elif hasattr(estimator, 'feature_importances_'):
coefs = estimator.feature_importances_
else:
raise RuntimeError('The classifier does not expose '
'"coef_" or "feature_importances_" '
'attributes')
# Get ranks
if coefs.ndim > 1:
ranks = np.argsort(safe_sqr(coefs).sum(axis=0))
else:
ranks = np.argsort(safe_sqr(coefs))
# for sparse case ranks is matrix
ranks = np.ravel(ranks)
# Eliminate the worse features
if self.stepwise_selection and 0.0 < step < 1.0:
current_step_size = int(np.sum(support_) * step)
else:
current_step_size = step
threshold = min(current_step_size,
np.sum(support_) - n_features_to_select)
# Compute step score on the previous selection iteration
# because 'estimator' must use features
# that have not been eliminated yet
if step_score:
self.scores_.append(step_score(estimator, features))
support_[features[ranks][:threshold]] = False
ranking_[np.logical_not(support_)] += 1
# Set final attributes
features = np.arange(n_features)[support_]
self.estimator_ = clone(self.estimator)
if self.estimator_params:
self.estimator_.set_params(**self.estimator_params)
self.estimator_.fit(X[:, features], y)
# Compute step score when only n_features_to_select features left
if step_score:
self.scores_.append(step_score(self.estimator_, features))
self.n_features_ = support_.sum()
self.support_ = support_
self.ranking_ = ranking_
return self
def main():
parser = argparse.ArgumentParser()
parser.add_argument('--results-path', default='./bucket/results/')
parser.add_argument('--data')
parser.add_argument('--tissue', type=lambda x: re.sub(r'[\"\']', '', x) if x is not None else None)
parser.add_argument('--target')
parser.add_argument('--data-path', default='./bucket/data/')
parser.add_argument('--verbose', '-v', action='count')
parser.add_argument('--test-size', type=float, default=0.1)
parser.add_argument('--n-iter', type=int, default=1)
parser.add_argument('--n-folds', default=10, type=n_folds_parser)
parser.add_argument('--clf')
args = parser.parse_args()
result = {}
result.update(args.__dict__)
start_time = datetime.now().strftime("%d/%m/%y %H:%M:%S")
result['start_time'] = start_time
if args.verbose:
for key in result:
print('# {}: {}'.format(key, result[key]))
print('# Running in: ' + gethostname())
print('# Start: ' + start_time)
experiment_id = hash(json.dumps(result) + str(np.random.rand(10, 1)))
result_file = join(args.results_path, 'rfe_{}.json'.format(experiment_id))
if args.verbose:
print('Results will be saved to {}'.format(result_file))
load_params = {}
if args.data == 'epi_ad':
load_params = {'read_original': True, 'skip_pickle': True}
data, factors = load(args.data, data_path=args.data_path, log=result, **load_params)
if args.tissue:
data = data[factors['source tissue'] == args.tissue]
factors = factors[factors['source tissue'] == args.tissue]
target = factors[args.target]
clf, param_grid = choose_classifier(args.clf, result, args.verbose)
split = StratifiedShuffleSplit(target, n_iter=args.n_iter, test_size=args.test_size)
n_features = data.shape[1]
n_features_to_select = 9
preprocess_steps = [('scaler', StandardScaler())]
# RFE
d0 = datetime.now()
result['experiments'] = []
for i, (train, test) in enumerate(split):
if args.verbose:
print('### ITERATION {}'.format(i))
result['experiments'].append({
'iteration': i,
'train_samples': data.index[train].tolist(),
'subsets': []
})
support_ = np.ones(n_features, dtype=np.bool)
ranking_ = np.ones(n_features, dtype=np.int)
for step in subset_sizes(n_features, n_features_to_select):
if args.verbose:
print('[{}] Evaluating with {} features and selecting {}.'
.format(datetime.now() - d0, np.sum(support_), np.sum(support_) - step))
# Train with current subset
pipeline = preprocess_steps + [('grid', GridWithCoef(clf, param_grid, cv=args.n_folds))]
pipeline = Pipeline(pipeline)
features = np.arange(n_features)[support_]
pipeline.fit(data.iloc[train, features], target.iloc[train])
# Save results for current set of features
grid = pipeline.steps[-1][1]
result['experiments'][-1]['subsets'].append({
'n_features': np.sum(support_),
'features': data.columns[features].tolist(),
'best_params': grid.best_params_,
'train': {
'y_true': target.iloc[train].tolist(),
'y_pred': grid.predict(data.iloc[train, features]).tolist()
},
'test': {
'y_true': target.iloc[test].tolist(),
'y_pred': grid.predict(data.iloc[test, features]).tolist()
}
})
# Select best subset
coef_ = safe_sqr(grid.coef_)
if coef_.ndim > 1:
ranks = np.argsort(coef_.sum(axis=0))
else:
ranks = np.argsort(coef_)
# for sparse case ranks is matrix
ranks = np.ravel(ranks)
# Eliminate the worse features
support_[features[ranks][:step]] = False
ranking_[np.logical_not(support_)] += 1
# Store results
with open(result_file, 'w') as f:
json.dump(result, f, sort_keys=True, indent=2, separators=(',', ': '))
if args.verbose:
print('# OK')
def main():
parser = argparse.ArgumentParser()
parser.add_argument('--results-path', default='./bucket/results/')
parser.add_argument('--data')
parser.add_argument('--target')
parser.add_argument('--data-path', default='./bucket/data/')
parser.add_argument('--verbose', '-v', action='count')
parser.add_argument('--test-size', type=float, default=0.1)
parser.add_argument('--n-iter', type=int, default=1)
parser.add_argument('--n-folds', default=10, type=n_folds_parser)
parser.add_argument('--clf')
args = parser.parse_args()
result = {}
result.update(args.__dict__)
if args.verbose:
for key in result:
print('# {}: {}'.format(key, result[key]))
print('# Start: ' + datetime.now().strftime("%d/%m/%y %H:%M:%S"))
result['selections'] = []
experiment_id = hash(json.dumps(result) + str(np.random.rand(10)))
result_file = join(args.results_path, 'fs_{}.json'.format(experiment_id))
if args.verbose:
print('Results will be saved to {}'.format(result_file))
data, factors = load(args.data, data_path=args.data_path, log=result)
target = factors[args.target]
clf, param_grid = choose_classifier(args.clf, result, args.verbose)
feature_names = data.columns
split = StratifiedShuffleSplit(target,
n_iter=args.n_iter,
test_size=args.test_size)
n_features = data.shape[1]
n_features_to_select = 1
support_ = np.ones(n_features, dtype=np.bool)
ranking_ = np.ones(n_features, dtype=np.int)
# Elimination
t0 = time()
d0 = datetime.now()
while np.sum(support_) > n_features_to_select:
step = 10**int(np.log10(np.sum(support_) - 1))
odd_step = np.sum(support_) - step * (np.sum(support_) // step)
if odd_step > 0:
step = odd_step
if args.verbose:
print('[{}] Selecting best {:d} features.'.format(
datetime.now() - d0,
np.sum(support_) - step))
# Remaining features
features = np.arange(n_features)[support_]
coef_ = None
test_scores = []
for train, test in split:
# Rank the remaining features
if args.n_folds == 'loo':
cv = LeaveOneOut(len(train))
else:
cv = args.n_folds
estimator = GridWithCoef(clf, param_grid, cv=cv)
estimator.fit(data.iloc[train, features], target.iloc[train])
if coef_ is None:
coef_ = safe_sqr(estimator.coef_)
else:
coef_ += safe_sqr(estimator.coef_)
test_scores.append(
estimator.score(data.iloc[test, features], target.iloc[test]))
if coef_.ndim > 1:
ranks = np.argsort(coef_.sum(axis=0))
else:
ranks = np.argsort(coef_)
# for sparse case ranks is matrix
ranks = np.ravel(ranks)
# Eliminate the worse features
threshold = min(step, np.sum(support_) - n_features_to_select)
support_[features[ranks][:threshold]] = False
ranking_[np.logical_not(support_)] += 1
result['selections'].append({
'scores':
test_scores,
'n_features':
np.sum(support_),
'features':
feature_names[support_].tolist()
})
with open(result_file, 'w') as f:
json.dump(result,
f,
sort_keys=True,
indent=2,
separators=(',', ': '))
if args.verbose:
print('# OK')
def _fit(self, X, y, step_score=None):
#X, y = check_X_y(X, y, "csc")
# Initialization
n_features = X.shape[1]
if self.n_features_to_select is None:
n_features_to_select = n_features // 2
else:
n_features_to_select = self.n_features_to_select
if 0.0 < self.step < 1.0:
step = int(max(1, self.step * n_features))
else:
step = int(self.step)
if step <= 0:
raise ValueError("Step must be >0")
if self.estimator_params is not None:
warnings.warn("The parameter 'estimator_params' is deprecated as "
"of version 0.16 and will be removed in 0.18. The "
"parameter is no longer necessary because the value "
"is set via the estimator initialisation or "
"set_params method.", DeprecationWarning)
support_ = np.zeros(n_features, dtype=np.bool)
support_[0] = True
ranking_ = np.zeros(n_features, dtype=np.int)
ranking_[0] = 1
if step_score:
self.scores_ = []
# Elimination
while np.sum(support_) < n_features_to_select:
# Remaining features
features = np.arange(n_features)[support_]
# Rank the remaining features
estimator = clone(self.estimator)
if self.estimator_params:
estimator.set_params(**self.estimator_params)
if self.verbose > 0:
print("Fitting estimator with %d features." % np.sum(support_))
estimator.fit(X[:, features], y)
# Get coefs
if hasattr(estimator, 'coef_'):
coefs = estimator.coef_
elif hasattr(estimator, 'feature_importances_'):
coefs = estimator.feature_importances_
else:
raise RuntimeError('The classifier does not expose '
'"coef_" or "feature_importances_" '
'attributes')
# Get ranks
if coefs.ndim > 1:
ranks = np.argsort(safe_sqr(coefs).sum(axis=0))[::-1]
else:
ranks = np.argsort(safe_sqr(coefs))[::-1]
# for sparse case ranks is matrix
ranks = np.ravel(ranks)
# Eliminate the worse features
threshold = min(step, n_features_to_select - np.sum(support_))
# Compute step score on the previous selection iteration
# because 'estimator' must use features
# that have not been eliminated yet
if step_score:
self.scores_.append(step_score(estimator, features))
support_[features[ranks][:threshold]] = True
ranking_[np.logical_not(support_)] += 1
# Set final attributes
features = np.arange(n_features)[support_]
self.estimator_ = clone(self.estimator)
if self.estimator_params:
self.estimator_.set_params(**self.estimator_params)
self.estimator_.fit(X[:, features], y)
# Compute step score when only n_features_to_select features left
if step_score:
self.scores_.append(step_score(self.estimator_, features))
self.n_features_ = support_.sum()
self.support_ = support_
self.ranking_ = ranking_
return self
def _fit(self, X, y, step_score=None):
# Parameter step_score controls the calculation of self.scores_
# step_score is not exposed to users
# and is used when implementing RFECV
# self.scores_ will not be calculated when calling _fit through fit
X, y = check_X_y(X, y, "csc", ensure_min_features=2)
# Initialization
n_features = X.shape[1]
if self.n_features_to_select is None:
n_features_to_select = n_features // 2
else:
n_features_to_select = self.n_features_to_select
# if 0.0 < self.step < 1.0:
# step = int(max(1, self.step * n_features))
# else:
# step = int(self.step)
# if step <= 0:
# raise ValueError("Step must be >0")
support_ = np.ones(n_features, dtype=np.bool)
ranking_ = np.ones(n_features, dtype=np.int)
if step_score:
self.scores_ = []
# Elimination
while np.sum(support_) > n_features_to_select:
if 0.0 < self.step < 1.0:
step = int(max(1, self.step * np.sum(support_)))
else:
step = int(self.step)
if step <= 0:
raise ValueError("Step must be >0")
# Remaining features
features = np.arange(n_features)[support_]
# Rank the remaining features
estimator = clone(self.estimator)
if self.verbose > 0:
print("Fitting estimator with %d features." % np.sum(support_))
estimator.fit(X[:, features], y)
# Get coefs
if hasattr(estimator, 'coef_'):
coefs = estimator.coef_
else:
coefs = getattr(estimator, 'feature_importances_', None)
if coefs is None:
raise RuntimeError('The classifier does not expose '
'"coef_" or "feature_importances_" '
'attributes')
#print(coefs)
# Get ranks
if coefs.ndim > 1:
ranks = np.argsort(safe_sqr(coefs).sum(axis=0))
else:
ranks = np.argsort(safe_sqr(coefs))
# for sparse case ranks is matrix
ranks = np.ravel(ranks)
# Eliminate the worse features
if np.sum(support_) <= 2 * n_features_to_select:
threshold = 1
else:
threshold = min(step, np.sum(support_) - n_features_to_select)
# Compute step score on the previous selection iteration
# because 'estimator' must use features
# that have not been eliminated yet
if step_score:
self.scores_.append(step_score(estimator, features))
print(threshold)
support_[features[ranks][:threshold]] = False
ranking_[np.logical_not(support_)] += 1
# Set final attributes
features = np.arange(n_features)[support_]
self.estimator_ = clone(self.estimator)
self.estimator_.fit(X[:, features], y)
# Compute step score when only n_features_to_select features left
if step_score:
self.scores_.append(step_score(self.estimator_, features))
self.n_features_ = support_.sum()
self.support_ = support_
self.ranking_ = ranking_
return self
def _fit(self, X, y, step_score=None):
if type(self.step) is not list:
return super(DyRFE, self)._fit(X, y, step_score)
# dynamic step
X, y = check_X_y(X, y, "csc")
# Initialization
n_features = X.shape[1]
if self.n_features_to_select is None:
n_features_to_select = n_features // 2
else:
n_features_to_select = self.n_features_to_select
step = []
for s in self.step:
if 0.0 < s < 1.0:
step.append(int(max(1, s * n_features)))
else:
step.append(int(s))
if s <= 0:
raise ValueError("Step must be >0")
support_ = np.ones(n_features, dtype=np.bool)
ranking_ = np.ones(n_features, dtype=np.int)
if step_score:
self.scores_ = []
step_i = 0
# Elimination
while np.sum(support_) > n_features_to_select and step_i < len(step):
# if last step is 1, will keep loop
if step_i == len(step) - 1 and step[step_i] != 0:
step.append(step[step_i])
# Remaining features
features = np.arange(n_features)[support_]
# Rank the remaining features
estimator = clone(self.estimator)
if self.verbose > 0:
print("Fitting estimator with %d features." % np.sum(support_))
estimator.fit(X[:, features], y)
# Get coefs
if hasattr(estimator, 'coef_'):
coefs = estimator.coef_
else:
coefs = getattr(estimator, 'feature_importances_', None)
if coefs is None:
raise RuntimeError('The classifier does not expose '
'"coef_" or "feature_importances_" '
'attributes')
# Get ranks
if coefs.ndim > 1:
ranks = np.argsort(safe_sqr(coefs).sum(axis=0))
else:
ranks = np.argsort(safe_sqr(coefs))
# for sparse case ranks is matrix
ranks = np.ravel(ranks)
# Eliminate the worse features
threshold =\
min(step[step_i], np.sum(support_) - n_features_to_select)
# Compute step score on the previous selection iteration
# because 'estimator' must use features
# that have not been eliminated yet
if step_score:
self.scores_.append(step_score(estimator, features))
support_[features[ranks][:threshold]] = False
ranking_[np.logical_not(support_)] += 1
step_i += 1
# Set final attributes
features = np.arange(n_features)[support_]
self.estimator_ = clone(self.estimator)
self.estimator_.fit(X[:, features], y)
# Compute step score when only n_features_to_select features left
if step_score:
self.scores_.append(step_score(self.estimator_, features))
self.n_features_ = support_.sum()
self.support_ = support_
self.ranking_ = ranking_
return self
def _fit(self, x_data, y_data, step_score=None, **fit_kwargs):
"""Expand :meth:`_fit` to accept kwargs."""
# Parameter step_score controls the calculation of self.scores_
# step_score is not exposed to users
# and is used when implementing AdvancedRFECV
# self.scores_ will not be calculated when calling _fit through fit
tags = self._get_tags()
x_data, y_data = check_X_y(
x_data,
y_data,
"csc",
ensure_min_features=2,
force_all_finite=not tags.get('allow_nan', True))
# Initialization
n_features = x_data.shape[1]
if self.n_features_to_select is None:
n_features_to_select = n_features // 2
else:
n_features_to_select = self.n_features_to_select
if 0.0 < self.step < 1.0:
step = int(max(1, self.step * n_features))
else:
step = int(self.step)
if step <= 0:
raise ValueError("Step must be >0")
support_ = np.ones(n_features, dtype=np.bool)
ranking_ = np.ones(n_features, dtype=np.int)
if step_score:
self.scores_ = []
# Elimination
while np.sum(support_) > n_features_to_select:
# Remaining features
features = np.arange(n_features)[support_]
# Rank the remaining features
estimator = clone(self.estimator)
if self.verbose > 0:
print("Fitting estimator with %d features." % np.sum(support_))
_update_transformers_param(estimator, support_)
estimator.fit(x_data[:, features], y_data, **fit_kwargs)
# Get coefs (hasattr(estimator, 'coef_') raises a KeyError for
# XGBRegressor models
try:
coefs = estimator.coef_
except (AttributeError, KeyError):
coefs = getattr(estimator, 'feature_importances_', None)
if coefs is None:
raise RuntimeError('The classifier does not expose '
'"coef_" or "feature_importances_" '
'attributes')
# Get ranks
if coefs.ndim > 1:
ranks = np.argsort(safe_sqr(coefs).sum(axis=0))
else:
ranks = np.argsort(safe_sqr(coefs))
# for sparse case ranks is matrix
ranks = np.ravel(ranks)
# Eliminate the worse features
threshold = min(step, np.sum(support_) - n_features_to_select)
# Compute step score on the previous selection iteration
# because 'estimator' must use features
# that have not been eliminated yet
if step_score:
self.scores_.append(step_score(estimator, features))
support_[features[ranks][:threshold]] = False
ranking_[np.logical_not(support_)] += 1
# Set final attributes
features = np.arange(n_features)[support_]
self.estimator_ = clone(self.estimator)
_update_transformers_param(self.estimator_, support_)
self.estimator_.fit(x_data[:, features], y_data, **fit_kwargs)
# Compute step score when only n_features_to_select features left
if step_score:
self.scores_.append(step_score(self.estimator_, features))
self.n_features_ = support_.sum()
self.support_ = support_
self.ranking_ = ranking_
return self
def _fit(self, X, y, step_score=None):
# Parameter step_score controls the calculation of self.scores_
# step_score is not exposed to users
# and is used when implementing RFECV
# self.scores_ will not be calculated when calling _fit through fit
# X, y = check_X_y(X, y, "csc")
X = pd.DataFrame(X)
n_samples, n_features = X.shape
if self.n_features_to_select is None:
n_features_to_select = n_features // 2
else:
n_features_to_select = self.n_features_to_select
support_ = np.ones(n_features, dtype=np.bool)
ranking_ = np.ones(n_features, dtype=np.int)
if step_score:
self.scores_ = []
# compute correlation matrix
# and sort feature by highest mean squared correlation
C = np.square(np.corrcoef(X.T) - np.diag(np.ones(X.shape[1])))
C = np.nan_to_num(C, nan=1)
coefs = C.mean(axis=1)
# Get ranks
ranks = np.argsort(-safe_sqr(coefs))
worst_feature = 0
# Recursive elimination
i = 1
while np.sum(support_) > n_features_to_select:
if worst_feature == n_features:
break
support_[ranks[worst_feature]] = False
X_worse = X.iloc[:, ranks[worst_feature]]
correlation_to_worst_feature = -C[:, ranks[worst_feature]]
correlation_to_worst_feature[support_ == False] = 0
most_related_features = np.argsort(correlation_to_worst_feature)
sorted_support = support_[most_related_features]
if self.min_corr < np.max(-correlation_to_worst_feature):
sorted_support = sorted_support & (
-correlation_to_worst_feature[most_related_features] >
self.min_corr)
X_reduced = X.iloc[:, most_related_features[sorted_support]]
if self.n_splits > n_samples:
skf = KFold(n_splits=self.n_splits,
shuffle=True,
random_state=self.random_state)
train_index, val_index = [
split for split in skf.split(X_worse)
][0]
X_train, X_val = X_reduced.iloc[train_index], X_reduced.iloc[
val_index]
y_train, y_val = X_worse[train_index], X_worse[val_index]
else:
X_train, X_val = X_reduced, X_reduced
y_train, y_val = X_worse, X_worse
# Eliminate predictable features
if self.verbose > 0:
print("Fitting estimator with %d features (%d/%d)" %
(np.sum(support_), i, n_features))
i += 1
estimator = clone(self.estimator)
estimator.fit(X_train, y_train)
score = estimator.score(X_val, y_val)
if score >= self.base_score:
# Compute step score on the previous selection iteration
# because 'estimator' must use features
# that have not been eliminated yet
ranking_[np.logical_not(support_)] += 1
else:
support_[ranks[worst_feature]] = True
worst_feature += 1
self.n_features_ = support_.sum()
self.support_ = support_
self.ranking_ = ranking_
return self
def main():
parser = argparse.ArgumentParser()
parser.add_argument('--results-path', default='./bucket/results/')
parser.add_argument('--data')
parser.add_argument('--target')
parser.add_argument('--data-path', default='./bucket/data/')
parser.add_argument('--verbose', '-v', action='count')
parser.add_argument('--test-size', type=float, default=0.1)
parser.add_argument('--n-iter', type=int, default=1)
parser.add_argument('--n-folds', default=10, type=n_folds_parser)
parser.add_argument('--clf')
args = parser.parse_args()
result = {}
result.update(args.__dict__)
if args.verbose:
for key in result:
print('# {}: {}'.format(key, result[key]))
print('# Start: ' + datetime.now().strftime("%d/%m/%y %H:%M:%S"))
result['selections'] = []
experiment_id = hash(json.dumps(result) + str(np.random.rand(10)))
result_file = join(args.results_path, 'fs_{}.json'.format(experiment_id))
if args.verbose:
print('Results will be saved to {}'.format(result_file))
data, factors = load(args.data, data_path=args.data_path, log=result)
target = factors[args.target]
clf, param_grid = choose_classifier(args.clf, result, args.verbose)
feature_names = data.columns
split = StratifiedShuffleSplit(target, n_iter=args.n_iter, test_size=args.test_size)
n_features = data.shape[1]
n_features_to_select = 1
support_ = np.ones(n_features, dtype=np.bool)
ranking_ = np.ones(n_features, dtype=np.int)
# Elimination
t0 = time()
d0 = datetime.now()
while np.sum(support_) > n_features_to_select:
step = 10 ** int(np.log10(np.sum(support_) - 1))
odd_step = np.sum(support_) - step * (np.sum(support_) // step)
if odd_step > 0:
step = odd_step
if args.verbose:
print('[{}] Selecting best {:d} features.'
.format(datetime.now() - d0, np.sum(support_) - step))
# Remaining features
features = np.arange(n_features)[support_]
coef_ = None
test_scores = []
for train, test in split:
# Rank the remaining features
if args.n_folds == 'loo':
cv = LeaveOneOut(len(train))
else:
cv = args.n_folds
estimator = GridWithCoef(clf, param_grid, cv=cv)
estimator.fit(data.iloc[train, features], target.iloc[train])
if coef_ is None:
coef_ = safe_sqr(estimator.coef_)
else:
coef_ += safe_sqr(estimator.coef_)
test_scores.append(estimator.score(data.iloc[test, features], target.iloc[test]))
if coef_.ndim > 1:
ranks = np.argsort(coef_.sum(axis=0))
else:
ranks = np.argsort(coef_)
# for sparse case ranks is matrix
ranks = np.ravel(ranks)
# Eliminate the worse features
threshold = min(step, np.sum(support_) - n_features_to_select)
support_[features[ranks][:threshold]] = False
ranking_[np.logical_not(support_)] += 1
result['selections'].append({
'scores': test_scores,
'n_features': np.sum(support_),
'features': feature_names[support_].tolist()
})
with open(result_file, 'w') as f:
json.dump(result, f, sort_keys=True, indent=2, separators=(',', ': '))
if args.verbose:
print('# OK')
def main():
parser = argparse.ArgumentParser()
parser.add_argument('--results-path', default='./bucket/results/')
parser.add_argument('--data')
parser.add_argument('--tissue',
type=lambda x: re.sub(r'[\"\']', '', x)
if x is not None else None)
parser.add_argument('--target')
parser.add_argument('--data-path', default='./bucket/data/')
parser.add_argument('--verbose', '-v', action='count')
parser.add_argument('--test-size', type=float, default=0.1)
parser.add_argument('--n-iter', type=int, default=1)
parser.add_argument('--n-folds', default=10, type=n_folds_parser)
parser.add_argument('--clf')
args = parser.parse_args()
result = {}
result.update(args.__dict__)
start_time = datetime.now().strftime("%d/%m/%y %H:%M:%S")
result['start_time'] = start_time
if args.verbose:
for key in result:
print('# {}: {}'.format(key, result[key]))
print('# Running in: ' + gethostname())
print('# Start: ' + start_time)
experiment_id = hash(json.dumps(result) + str(np.random.rand(10, 1)))
result_file = join(args.results_path, 'rfe_{}.json'.format(experiment_id))
if args.verbose:
print('Results will be saved to {}'.format(result_file))
load_params = {}
if args.data == 'epi_ad':
load_params = {'read_original': True, 'skip_pickle': True}
data, factors = load(args.data,
data_path=args.data_path,
log=result,
**load_params)
if args.tissue:
data = data[factors['source tissue'] == args.tissue]
factors = factors[factors['source tissue'] == args.tissue]
target = factors[args.target]
clf, param_grid = choose_classifier(args.clf, result, args.verbose)
split = StratifiedShuffleSplit(target,
n_iter=args.n_iter,
test_size=args.test_size)
n_features = data.shape[1]
n_features_to_select = 9
preprocess_steps = [('scaler', StandardScaler())]
# RFE
d0 = datetime.now()
result['experiments'] = []
for i, (train, test) in enumerate(split):
if args.verbose:
print('### ITERATION {}'.format(i))
result['experiments'].append({
'iteration':
i,
'train_samples':
data.index[train].tolist(),
'subsets': []
})
support_ = np.ones(n_features, dtype=np.bool)
ranking_ = np.ones(n_features, dtype=np.int)
for step in subset_sizes(n_features, n_features_to_select):
if args.verbose:
print('[{}] Evaluating with {} features and selecting {}.'.
format(datetime.now() - d0, np.sum(support_),
np.sum(support_) - step))
# Train with current subset
pipeline = preprocess_steps + [
('grid', GridWithCoef(clf, param_grid, cv=args.n_folds))
]
pipeline = Pipeline(pipeline)
features = np.arange(n_features)[support_]
pipeline.fit(data.iloc[train, features], target.iloc[train])
# Save results for current set of features
grid = pipeline.steps[-1][1]
result['experiments'][-1]['subsets'].append({
'n_features':
np.sum(support_),
'features':
data.columns[features].tolist(),
'best_params':
grid.best_params_,
'train': {
'y_true': target.iloc[train].tolist(),
'y_pred': grid.predict(data.iloc[train,
features]).tolist()
},
'test': {
'y_true': target.iloc[test].tolist(),
'y_pred': grid.predict(data.iloc[test, features]).tolist()
}
})
# Select best subset
coef_ = safe_sqr(grid.coef_)
if coef_.ndim > 1:
ranks = np.argsort(coef_.sum(axis=0))
else:
ranks = np.argsort(coef_)
# for sparse case ranks is matrix
ranks = np.ravel(ranks)
# Eliminate the worse features
support_[features[ranks][:step]] = False
ranking_[np.logical_not(support_)] += 1
# Store results
with open(result_file, 'w') as f:
json.dump(result,
f,
sort_keys=True,
indent=2,
separators=(',', ': '))
if args.verbose:
print('# OK')
def _fit(self, X, y, step_score=None):
tags = self._get_tags()
X, y = self._validate_data(
X,
y,
accept_sparse="csc",
ensure_min_features=2,
force_all_finite=not tags.get('allow_nan', True),
multi_output=True)
# Initialization
n_features = X.shape[1]
if self.n_features_to_select is None:
n_features_to_select = n_features // 2
else:
n_features_to_select = self.n_features_to_select
if 0.0 < self.step < 1.0: step = int(max(1, self.step * n_features))
else: step = int(self.step)
if step <= 0: raise ValueError("Step must be >0")
support_ = np.ones(n_features, dtype=np.bool)
ranking_ = np.ones(n_features, dtype=np.int)
if step_score: self.scores_ = []
# Elimination
while np.sum(support_) > n_features_to_select:
# Remaining features
features = np.arange(n_features)[support_]
# Rank the remaining features
estimator = clone(self.estimator)
if self.verbose > 0:
print("Fitting estimator with %d features." % np.sum(support_))
# Fit
estimator.fit(X[:, features], y)
# Get coefs
if hasattr(estimator, 'coef_'): coefs = estimator.coef_
else: coefs = getattr(estimator, 'feature_importances_', None)
if coefs is None:
raise RuntimeError(
"The classifier does not expose coef_or feature_importances_attributes"
)
# Get ranks
if coefs.ndim > 1: ranks = np.argsort(safe_sqr(coefs).sum(axis=0))
else: ranks = np.argsort(safe_sqr(coefs))
# For sparse case ranks is matrix
ranks = np.ravel(ranks)
# Eliminate the worse features
threshold = min(step, np.sum(support_) - n_features_to_select)
# Save support of selected features
self.supports.append(list(support_))
# Compute step score on the previous selection iteration because 'estimator' must use features that have not been eliminated yet
if step_score: self.scores_.append(step_score(estimator, features))
support_[features[ranks][:threshold]] = False
ranking_[np.logical_not(support_)] += 1
# Set final attributes
features = np.arange(n_features)[support_]
self.estimator_ = clone(self.estimator)
self.estimator_.fit(X[:, features], y)
# Compute step score when only n_features_to_select features left
if step_score:
self.scores_.append(step_score(self.estimator_, features))
self.n_features_ = support_.sum()
self.support_ = support_
self.ranking_ = ranking_
# Save support of selected features
self.supports.append(list(support_))
return self
def f_regression_cov_alt(X, y, C):
"""
Implementation as derived in tex document
See pg 12 of following document for definition of F-statistic
http://www-stat.stanford.edu/~jtaylo/courses/stats191/notes/simple_diagnostics.pdf
Parameters
----------
X : {array-like, sparse matrix} shape = (n_samples, n_features)
The set of regressors that will tested sequentially.
y : array of shape(n_samples).
The data matrix
c : {array-like, sparse matrix} shape = (n_samples, n_covariates)
The set of covariates.
Returns
-------
F : array, shape=(n_features,)
F values of features.
pval : array, shape=(n_features,)
p-values of F-scores.
"""
# make sure we don't overwrite input data
old_flag_X = X.flags.writeable
old_flag_C = C.flags.writeable
old_flag_y = y.flags.writeable
X.flags.writeable = False
C.flags.writeable = False
y.flags.writeable = False
#X, C, y = check_array(X, C, y, dtype=np.float)
y = y.ravel()
# make copy of input data
X = X.copy(order="F")
y = y.copy()
assert C.shape[1] < C.shape[0]
cpinv = np.linalg.pinv(C)
X -= np.dot(C, (np.dot(cpinv, X))) #most expensive line (runtime)
y -= np.dot(C, (np.dot(cpinv, y)))
yS = safe_sqr(y.T.dot(X)) # will create a copy
# Note: (X*X).sum(0) = X.T.dot(X).diagonal(), computed efficiently
# see e.g.: http://stackoverflow.com/questions/14758283/is-there-a-numpy-scipy-dot-product-calculating-only-the-diagonal-entries-of-the
# TODO: make this smarter using either stride tricks or cython
X *= X
denom = X.sum(0) * y.T.dot(y) - yS
F = yS / denom
# degrees of freedom
dof = (X.shape[0] - 1 - C.shape[1]) / (1) #(df_fm / (df_rm - df_fm))
F *= dof
# convert to p-values
pv = stats.f.sf(F, 1, dof)
# restore old state
X.flags.writeable = old_flag_X
C.flags.writeable = old_flag_C
y.flags.writeable = old_flag_y
return F, pv
def _fit(self, X, y, step_score=None):
if type(self.step) is not list:
return super(DyRFE, self)._fit(X, y, step_score)
# dynamic step
X, y = check_X_y(X, y, "csc")
# Initialization
n_features = X.shape[1]
if self.n_features_to_select is None:
n_features_to_select = n_features // 2
else:
n_features_to_select = self.n_features_to_select
step = []
for s in self.step:
if 0.0 < s < 1.0:
step.append(int(max(1, s * n_features)))
else:
step.append(int(s))
if s <= 0:
raise ValueError("Step must be >0")
support_ = np.ones(n_features, dtype=np.bool)
ranking_ = np.ones(n_features, dtype=np.int)
if step_score:
self.scores_ = []
step_i = 0
# Elimination
while np.sum(support_) > n_features_to_select and step_i < len(step):
# if last step is 1, will keep loop
if step_i == len(step) - 1 and step[step_i] != 0:
step.append(step[step_i])
# Remaining features
features = np.arange(n_features)[support_]
# Rank the remaining features
estimator = clone(self.estimator)
if self.verbose > 0:
print("Fitting estimator with %d features." % np.sum(support_))
estimator.fit(X[:, features], y)
# Get coefs
if hasattr(estimator, 'coef_'):
coefs = estimator.coef_
else:
coefs = getattr(estimator, 'feature_importances_', None)
if coefs is None:
raise RuntimeError('The classifier does not expose '
'"coef_" or "feature_importances_" '
'attributes')
# Get ranks
if coefs.ndim > 1:
ranks = np.argsort(safe_sqr(coefs).sum(axis=0))
else:
ranks = np.argsort(safe_sqr(coefs))
# for sparse case ranks is matrix
ranks = np.ravel(ranks)
# Eliminate the worse features
threshold =\
min(step[step_i], np.sum(support_) - n_features_to_select)
# Compute step score on the previous selection iteration
# because 'estimator' must use features
# that have not been eliminated yet
if step_score:
self.scores_.append(step_score(estimator, features))
support_[features[ranks][:threshold]] = False
ranking_[np.logical_not(support_)] += 1
step_i += 1
# Set final attributes
features = np.arange(n_features)[support_]
self.estimator_ = clone(self.estimator)
self.estimator_.fit(X[:, features], y)
# Compute step score when only n_features_to_select features left
if step_score:
self.scores_.append(step_score(self.estimator_, features))
self.n_features_ = support_.sum()
self.support_ = support_
self.ranking_ = ranking_
return self
def _fit(self,
X,
y,
features_names=None,
preload_features=None,
ranking_th=0.005):
X, y = check_X_y(X,
y,
accept_sparse=['csr', 'csc', 'coo'],
multi_output=True)
y = check_array(y, accept_sparse=['csr', 'csc', 'coo'])
# Initialization
n_features = X.shape[1]
features = np.arange(n_features)
cv = self.cv
cv = check_cv(cv, y, classifier=is_classifier(self.estimator))
if sklearn.__version__ == '0.17':
n_splits = cv.n_folds
else:
n_splits = cv.get_n_splits(X, y)
if self.verbose > 1:
print("Fitting {0} folds for each of iteration".format(n_splits))
if 0.0 < self.n_features_step < 1.0:
step = int(max(1, self.n_features_step * n_features))
else:
step = int(self.n_features_step)
if step <= 0:
raise ValueError("Step must be >0")
if features_names is not None:
features_names = np.array(features_names)
else:
if self.features_names is not None:
features_names = self.features_names
else:
features_names = np.arange(n_features) # use indices
tentative_support_ = np.zeros(n_features, dtype=np.bool)
current_support_ = np.zeros(n_features, dtype=np.bool)
self.scores_ = []
self.scores_confidences_ = []
self.features_per_it_ = []
if preload_features is not None:
preload_features = np.unique(preload_features).astype('int')
current_support_[preload_features] = True
tentative_support_[preload_features] = True
X_selected = X[:, features[current_support_]]
y_hat, cv_scores = my_cross_val_predict(clone(self.estimator),
X_selected,
y,
cv=cv)
target = y - y_hat
else:
target = y.copy()
score, confidence_interval = -np.inf, 0
proceed = np.sum(current_support_) < X.shape[1]
while proceed:
if self.verbose > 1:
print('\nN-times variance of target: {}'.format(
target.var() * target.shape[0]))
# update values
old_confidence_interval = confidence_interval
old_score = score
if self.scale:
target = StandardScaler().fit_transform(
target
) # Removed ravel to deal with multi-dimensional target
# target = StandardScaler().fit_transform(target.reshape(
# -1, 1)).ravel()
# target = MinMaxScaler().fit_transform(target.reshape(
# -1,1)).ravel()
if self.verbose > 1:
print()
print('Feature ranking')
print()
print("target shape: {}".format(target.shape))
print()
# Rank the remaining features
start_t = time.time()
rank_estimator = clone(self.estimator)
rank_estimator.fit(X, target)
end_fit = time.time() - start_t
# Get coefs
start_t = time.time()
if hasattr(rank_estimator, 'coef_'):
coefs = rank_estimator.coef_
elif hasattr(rank_estimator, 'feature_importances_'):
coefs = rank_estimator.feature_importances_
else:
raise RuntimeError('The classifier does not expose '
'"coef_" or "feature_importances_" '
'attributes')
end_rank = time.time() - start_t
# Get ranks by ordering in ascending way
if coefs.ndim > 1:
ranks = np.argsort(safe_sqr(coefs).sum(axis=0))
coefs = coefs.sum(axis=0)
else:
ranks = np.argsort(safe_sqr(coefs))
# for sparse case ranks is matrix
ranks = np.ravel(ranks)
if self.verbose > 1:
ranked_f = features[ranks]
if features_names is not None:
ranked_n = features_names[ranks]
else:
ranked_n = ['-'] * n_features
print('{:6}\t{:6}\t{:8}\t{}'.format('Rank', 'Index', 'Score',
'Feature Name'))
for i in range(n_features):
idx = n_features - i - 1
if (coefs[ranks[idx]] < ranking_th) and (i > 2):
print(' ...')
break
print('#{:6}\t{:6}\t{:6f}\t{}'.format(
str(i), str(ranked_f[idx]), coefs[ranks[idx]],
ranked_n[idx]))
print("\n Fit done in {} s and rank done in {} s".format(
end_fit, end_rank))
# if coefs[ranks][-1] < 1e-5:
# if self.verbose > 0:
# import warnings
# warnings.warn('scores are too small to be used, please standardize inputs')
# break
# get the best features (ie, the latest one)
# if the most ranked features is selected go on a select
# other features accordingly to the ranking
# threshold = step
# step_features = features[ranks][-threshold:]
ii = len(features_names) - 1
step_features = features[ranks][ii]
while np.all(current_support_[step_features]) and ii > 0:
ii -= 1
step_features = features[ranks][ii]
if np.all(current_support_[step_features]):
if self.verbose > 0:
print("Selected features: {} {}".format(
features_names[step_features], step_features))
# if features_names is not None:
# print("Selected features: {} {}".format(features_names[ranks][-threshold:], step_features))
# else:
# print("Selected features: {}".format(step_features))
print('Ended because selected features already selected')
step_features = None
break
# update selected features
tentative_support_[step_features] = True
# get the selected features
X_selected = X[:, features[tentative_support_]]
start_t = time.time()
# cross validates to obtain the scores
y_hat, cv_scores = my_cross_val_predict(clone(self.estimator),
X_selected,
y,
cv=cv)
# y_hat = cross_val_predict(clone(self.estimator), X_selected, y, cv=cv)
# compute new target
target = y - y_hat
# compute score and confidence interval
# score = r2_score(y_true=y, y_pred=y_hat, multioutput='uniform_average') # np.mean(cv_scores)
if self.verbose > 1:
print('r2: {}'.format(np.mean(cv_scores, axis=0)))
score = np.mean(cv_scores)
if len(cv_scores.shape) > 1:
cv_scores = np.mean(cv_scores, axis=1)
m2 = np.mean(cv_scores * cv_scores)
confidence_interval_or = np.sqrt(
(m2 - score * score) / (n_splits - 1))
end_t = time.time() - start_t
if self.verbose > 0:
# if features_names is not None:
print("Selected features: {} {}".format(
features_names[step_features], step_features))
print("Total features: {} {}".format(
features_names[tentative_support_],
features[tentative_support_]))
# else:
# print("Selected features: {}".format(step_features))
# print("Total features: {}".format(features[tentative_support_]))
print("R2= {} +- {}".format(score, confidence_interval_or))
print("\nCrossvalidation done in {} s".format(end_t))
confidence_interval = confidence_interval_or * self.significance # do not trust confidence interval completely
# check terminal condition
proceed = score - old_score > old_confidence_interval + confidence_interval if score >= 0 and old_score >= 0 else True
if self.verbose > 1:
print("PROCEED: {}\n\t{} - {} > {} + {}\n\t{} > {} )".format(
proceed, score, old_score, old_confidence_interval,
confidence_interval, score - old_score,
old_confidence_interval + confidence_interval))
if proceed or np.sum(current_support_) == 0:
# last feature set proved to be informative
# we need to take into account of the new features (update current support)
current_support_[step_features] = True
self.features_per_it_.append(features_names[step_features])
self.scores_.append(score)
self.scores_confidences_.append(confidence_interval)
# all the features are selected, stop
if np.sum(current_support_) == n_features:
if self.verbose > 0:
print("All the features has been selected.")
proceed = False
else:
# last feature set proved to be not informative
# keep old support and delete the current one (it is no more necessary)
del tentative_support_
if self.verbose > 0:
print('Last feature {} not added to the set'.format(
features_names[step_features]))
# Set final attributes
self.estimator_ = clone(self.estimator)
# self.estimator_.fit(Xns[:, current_support_], yns)
self.estimator_.fit(X[:, current_support_], y)
self.n_features_ = current_support_.sum()
self.support_ = current_support_
# self.ranking_ = ranking_
return self
def fit(self, X, y=None, groups=None, **fit_params):
"""
Apply feature elimination routine, ultimately fitting
estimator on the best feature set.
Args:
X (array-like, shape = [n_samples, n_features]): input data
y (array-like, shape = [n_samples, ], [n_samples, n_classes]): targets
groups (array-like): group labels for the samples used while
splitting the dataset into train/test set
**fit_params (dict of string -> object): parameters passed
to the `fit` method of the estimator
"""
X, y = check_X_y(X, y, "csr", ensure_min_features=2)
cv = check_cv(self.cv, y, is_classifier(self.estimator))
scorer = check_scoring(self.estimator, scoring=self.scoring)
n_features = X.shape[1]
if self.min_features_to_select is None:
min_features_to_select = n_features // 2
else:
min_features_to_select = self.min_features_to_select
if 0.0 < self.step < 1.0:
step = int(max(1, self.step * n_features))
else:
step = int(self.step)
if step <= 0:
raise ValueError("Step must be >0")
initial_estimator = _clone(self.estimator)
initial_estimator.fit(X, y, **fit_params)
if hasattr(initial_estimator, 'coef_'):
coefs = initial_estimator.coef_
else:
coefs = getattr(initial_estimator, 'feature_importances_', None)
if coefs is None:
raise RuntimeError('The classifier does not expose '
'"coef_" or "feature_importances_" '
'attributes')
if coefs.ndim > 1:
ranks = np.argsort(safe_sqr(coefs).sum(axis=0))
else:
ranks = np.argsort(safe_sqr(coefs))
ranks = np.ravel(ranks)[:(n_features - min_features_to_select)]
this_step = 0
features_to_remove = [np.array([])]
while this_step < (n_features - min_features_to_select):
this_step += step
features_to_remove.append(ranks[:this_step])
cv_splits_ = list(cv.split(X,y,groups))
fit_sets = list(product(features_to_remove, cv_splits_))
base_estimator = _clone(self.estimator)
if not self.sc:
parallel = Parallel(
n_jobs=self.n_jobs, verbose=self.verbose,
pre_dispatch=self.pre_dispatch
)
scores = parallel(
delayed(_fit_and_score_one)(
index, _clone(base_estimator), X, y,
scorer, train, test, self.verbose,
fit_params)
for index, (train, test) in fit_sets)
score_sets = _divide_chunks(list(scores), len(cv_splits_))
else:
base_estimator_ = self.sc.broadcast(base_estimator)
partitions = _parse_partitions(self.partitions, len(fit_sets))
verbose = self.verbose
scores = (
self.sc.parallelize(fit_sets, numSlices=partitions)
.map(lambda x: [x[0], _fit_and_score_one(
x[0], _clone(base_estimator), X, y, scorer,
x[1][0], x[1][1], verbose, fit_params)]).collect()
)
score_sets = []
for feat_set in features_to_remove:
this_set = []
for row in scores:
if (feat_set.shape == row[0].shape) and np.allclose(feat_set, row[0]):
this_set.append(row[1])
score_sets.append(this_set)
self.scores_ = []
for score_set in score_sets:
this_score = np.mean(score_set)
self.scores_.append(this_score)
best_set_ = np.argmax(self.scores_)
self.best_score_ = self.scores_[best_set_]
if len(features_to_remove[best_set_]) > 0:
self.best_features_ = np.delete(
range(n_features), features_to_remove[best_set_])
else:
self.best_features_ = range(n_features)
self.best_estimator_ = _clone(self.estimator)
self.best_estimator_.fit(X[:, self.best_features_], y, **fit_params)
self.n_features_ = len(self.best_features_)
del self.sc
return self
def _fit(self, X, y, step_score=None, features_names=None):
X, y = check_X_y(X,
y,
accept_sparse=['csr', 'csc', 'coo'],
multi_output=True)
# Initialization
n_features = X.shape[1]
features = np.arange(n_features)
cv = self.cv
cv = check_cv(cv, y, classifier=is_classifier(self.estimator))
n_splits = cv.get_n_splits(X, y)
if self.verbose > 0:
print("Fitting {0} folds for each of iteration".format(n_splits))
if 0.0 < self.n_features_step < 1.0:
step = int(max(1, self.n_features_step * n_features))
else:
step = int(self.n_features_step)
if step <= 0:
raise ValueError("Step must be >0")
# if self.force_iterations is None:
# force_iteration = False
# else:
# force_iteration = self.force_iterations
# if step_score is None:
# step_score = r2_score
if features_names is not None:
features_names = np.array(features_names)
else:
if self.features_names is not None:
features_names = self.features_names
else:
features_names = np.arange(n_features) # use indices
tentative_support_ = np.zeros(n_features, dtype=np.bool)
current_support_ = np.zeros(n_features, dtype=np.bool)
self.scores_ = []
self.features_per_it_ = []
target = y
score, confidence_interval = -np.inf, 0
proceed = True
while proceed:
if self.verbose > 0:
print('\nN-times variance of target: {}'.format(
target.var() * target.shape[0]))
# update values
old_confidence_interval = confidence_interval
old_score = score
if self.verbose > 0:
print()
print('Feature ranking')
print()
if self.scale:
target = StandardScaler().fit_transform(target)
# Rank the remaining features
rank_estimator = clone(self.estimator)
rank_estimator.fit(X, target)
# Get coefs
if hasattr(rank_estimator, 'coef_'):
coefs = rank_estimator.coef_
elif hasattr(rank_estimator, 'feature_importances_'):
coefs = rank_estimator.feature_importances_
else:
raise RuntimeError('The classifier does not expose '
'"coef_" or "feature_importances_" '
'attributes')
# Get ranks by ordering in ascending way
if coefs.ndim > 1:
ranks = np.argsort(safe_sqr(coefs).sum(axis=0))
coefs = coefs.sum(axis=0)
else:
ranks = np.argsort(safe_sqr(coefs))
# for sparse case ranks is matrix
ranks = np.ravel(ranks)
if self.verbose > 0:
ranked_f = features[ranks]
if features_names is not None:
ranked_n = features_names[ranks]
else:
ranked_n = ['-'] * n_features
print('{:6}\t{:6}\t{:8}\t{}'.format('Rank', 'Index', 'Score',
'Feature Name'))
for i in range(n_features):
idx = n_features - i - 1
print('#{:6}\t{:6}\t{:6f}\t{}'.format(
str(i), str(ranked_f[idx]), coefs[ranks[idx]],
ranked_n[idx]))
if coefs[ranks][-1] < 1e-5:
if self.verbose > 0:
import warnings
warnings.warn(
'scores are too small to be used, please standardize inputs'
)
break
# get the best features (ie, the latest one)
# if the most ranked features is selected go on a select
# other features accordingly to the ranking
# threshold = step
# step_features = features[ranks][-threshold:]
ii = len(features_names) - 1
step_features = features[ranks][ii]
while np.all(current_support_[step_features]) and ii > 0:
ii -= 1
step_features = features[ranks][ii]
if np.all(current_support_[step_features]):
if self.verbose > 0:
print("Selected features: {} {}".format(
features_names[step_features], step_features))
# if features_names is not None:
# print("Selected features: {} {}".format(features_names[ranks][-threshold:], step_features))
# else:
# print("Selected features: {}".format(step_features))
print('Ended because selected features already selected')
step_features = None
break
# update selected features
tentative_support_[step_features] = True
# get the selected features
X_selected = X[:, features[tentative_support_]]
# cross validates to obtain the scores
# cv_scores = cross_val_score(clone(self.estimator), X_selected, y, cv=cv, scoring='r2')
y_hat = cross_val_predict(clone(self.estimator),
X_selected,
y,
cv=cv)
# compute new target
target = y - y_hat
# compute score and confidence interval
score = r2_score(
y_true=y, y_pred=y_hat,
multioutput='uniform_average') # np.mean(cv_scores)
print('r2: {}'.format(
r2_score(y_true=y, y_pred=y_hat, multioutput='raw_values')))
# m2 = np.mean(cv_scores * cv_scores)
SIGNIFICANCE = 0.0
confidence_interval = SIGNIFICANCE # * np.sqrt((m2 - score * score) / (n_splits - 1))
if self.verbose > 0:
# if features_names is not None:
print("Selected features: {} {}".format(
features_names[step_features], step_features))
print("Total features: {} {}".format(
features_names[tentative_support_],
features[tentative_support_]))
# else:
# print("Selected features: {}".format(step_features))
# print("Total features: {}".format(features[tentative_support_]))
print("R2= {} +- {}".format(score, confidence_interval))
self.scores_.append(score)
self.features_per_it_.append(features_names[tentative_support_])
# check terminal condition
proceed = score - old_score > old_confidence_interval + confidence_interval
if proceed or np.sum(current_support_) == 0:
# last feature set proved to be informative
# we need to take into account of the new features (update current support)
current_support_[step_features] = True
# all the features are selected, stop
if np.sum(current_support_) == n_features:
if self.verbose > 0:
print("All the features has been selected.")
proceed = False
else:
# last feature set proved to be not informative
# keep old support and delete the current one (it is no more necessary)
del tentative_support_
if self.verbose > 0:
print('Last feature {} not added to the set'.format(
features_names[step_features]))
# Set final attributes
self.estimator_ = clone(self.estimator)
# self.estimator_.fit(Xns[:, current_support_], yns)
self.estimator_.fit(X[:, current_support_], y)
self.n_features_ = current_support_.sum()
self.support_ = current_support_
# self.ranking_ = ranking_
return self
def f_oneway(*args):
"""Performs a 1-way ANOVA.
The one-way ANOVA tests the null hypothesis that 2 or more groups have
the same population mean. The test is applied to samples from two or
more groups, possibly with differing sizes.
Read more in the :ref:`User Guide <univariate_feature_selection>`.
Parameters
----------
*args : array_like, sparse matrices
sample1, sample2... The sample measurements should be given as
arguments.
Returns
-------
F-value : float
The computed F-value of the test.
p-value : float
The associated p-value from the F-distribution.
Notes
-----
The ANOVA test has important assumptions that must be satisfied in order
for the associated p-value to be valid.
1. The samples are independent
2. Each sample is from a normally distributed population
3. The population standard deviations of the groups are all equal. This
property is known as homoscedasticity.
If these assumptions are not true for a given set of data, it may still be
possible to use the Kruskal-Wallis H-test (`scipy.stats.kruskal`_) although
with some loss of power.
The algorithm is from Heiman[2], pp.394-7.
See ``scipy.stats.f_oneway`` that should give the same results while
being less efficient.
References
----------
.. [1] Lowry, Richard. "Concepts and Applications of Inferential
Statistics". Chapter 14.
http://faculty.vassar.edu/lowry/ch14pt1.html
.. [2] Heiman, G.W. Research Methods in Statistics. 2002.
"""
n_classes = len(args)
args = [as_float_array(a) for a in args]
n_samples_per_class = np.array([a.shape[0] for a in args])
n_samples = np.sum(n_samples_per_class)
ss_alldata = sum(safe_sqr(a).sum(axis=0) for a in args)
sums_args = [np.asarray(a.sum(axis=0)) for a in args]
square_of_sums_alldata = sum(sums_args)**2
square_of_sums_args = [s**2 for s in sums_args]
sstot = ss_alldata - square_of_sums_alldata / float(n_samples)
ssbn = 0.
for k, _ in enumerate(args):
ssbn += square_of_sums_args[k] / n_samples_per_class[k]
ssbn -= square_of_sums_alldata / float(n_samples)
sswn = sstot - ssbn
dfbn = n_classes - 1
dfwn = n_samples - n_classes
msb = ssbn / float(dfbn)
msw = sswn / float(dfwn)
constant_features_idx = np.where(msw == 0.)[0]
if (np.nonzero(msb)[0].size != msb.size and constant_features_idx.size):
warnings.warn("Features %s are constant." % constant_features_idx,
UserWarning)
f = msb / msw
# flatten matrix to vector in sparse case
f = np.asarray(f).ravel()
prob = special.fdtrc(dfbn, dfwn, f)
return f, prob
def svmFC(self, x, step):
self.step = step
self.X, self.y, self.X_val, self.y_val, self.featureNames = self.splitData(
x=x)
self.features = self.featureNames
self.j = 0
while self.X.shape[1] > 201:
self.j += 1
self.svc = SVC(kernel='linear')
self.Cs = np.array([0.5, 1.0, 10, 100])
# get the hyperparamaters
self.clf = GridSearchCV(estimator=self.svc,
param_grid=dict(C=self.Cs),
cv=5,
return_train_score=True,
n_jobs=20)
self.clf.fit(self.X, self.y)
# do 5-fold cross validation
self.cv_test_error = []
self.skf = StratifiedKFold(n_splits=5,
random_state=self.j,
shuffle=True)
for trn, tst in self.skf.split(self.X, self.y):
self.train_train, self.train_test = self.X[trn], self.X[tst]
self.train_clstrs, self.test_clstrs = self.y[trn], self.y[tst]
self.val_clf = SVC(C=list(self.clf.best_params_.values())[0],
kernel="linear")
self.val_clf.fit(self.train_train, self.train_clstrs)
self.cv_test_error.append(
self.val_clf.score(self.train_test, self.test_clstrs))
self.mean_cv_test_error = np.array(self.cv_test_error).mean()
## train classification for RFE
self.rfe_clf = SVC(C=list(self.clf.best_params_.values())[0],
kernel="linear")
self.rfe_clf.fit(self.X, self.y)
# get coeffs
self.coefs = self.rfe_clf.coef_
# get ranks
if self.coefs.ndim > 1:
self.ranks = np.argsort(safe_sqr(self.coefs).sum(axis=0))
else:
self.ranks = np.argsort(safe_sqr(self.coefs))
# remove the X least important features from the array
self.to_remove_index = []
for r in range(self.step):
self.to_remove_index.append(self.ranks[r])
self.to_remove_index.sort(reverse=True)
# remove from largest index to smallest
for f in self.to_remove_index:
self.X = np.delete(self.X, f, axis=1)
self.X_val = np.delete(self.X_val, f, axis=1)
del self.features[f]
return self.X, self.y, self.X_val, self.y_val, self.features
