本文整理汇总了Python中sklearn.utils.sparsefuncs.mean_variance_axis函数的典型用法代码示例。如果您正苦于以下问题：Python mean_variance_axis函数的具体用法？Python mean_variance_axis怎么用？Python mean_variance_axis使用的例子？那么恭喜您, 这里精选的函数代码示例或许可以为您提供帮助。
在下文中一共展示了mean_variance_axis函数的11个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于我们的系统推荐出更棒的Python代码示例。
示例1: test_mean_variance_axis1
def test_mean_variance_axis1():
X, _ = make_classification(5, 4, random_state=0)
# Sparsify the array a little bit
X[0, 0] = 0
X[2, 1] = 0
X[4, 3] = 0
X_lil = sp.lil_matrix(X)
X_lil[1, 0] = 0
X[1, 0] = 0
X_csr = sp.csr_matrix(X_lil)
X_means, X_vars = mean_variance_axis(X_csr, axis=1)
assert_array_almost_equal(X_means, np.mean(X, axis=1))
assert_array_almost_equal(X_vars, np.var(X, axis=1))
X_csc = sp.csc_matrix(X_lil)
X_means, X_vars = mean_variance_axis(X_csc, axis=1)
assert_array_almost_equal(X_means, np.mean(X, axis=1))
assert_array_almost_equal(X_vars, np.var(X, axis=1))
assert_raises(TypeError, mean_variance_axis, X_lil, axis=1)
X = X.astype(np.float32)
X_csr = X_csr.astype(np.float32)
X_csc = X_csr.astype(np.float32)
X_means, X_vars = mean_variance_axis(X_csr, axis=1)
assert_array_almost_equal(X_means, np.mean(X, axis=1))
assert_array_almost_equal(X_vars, np.var(X, axis=1))
X_means, X_vars = mean_variance_axis(X_csc, axis=1)
assert_array_almost_equal(X_means, np.mean(X, axis=1))
assert_array_almost_equal(X_vars, np.var(X, axis=1))
assert_raises(TypeError, mean_variance_axis, X_lil, axis=1)
开发者ID:Ablat，项目名称:scikit-learn，代码行数:32，代码来源:test_sparsefuncs.py
示例2: nanmean
def nanmean(x, axis=None):
""" Equivalent of np.nanmean that supports sparse or dense matrices. """
if not sp.issparse(x):
means = np.nanmean(x, axis=axis)
elif axis is None:
means, _ = mean_variance_axis(x, axis=0)
means = np.nanmean(means)
else:
means, _ = mean_variance_axis(x, axis=axis)
return means
开发者ID:biolab，项目名称:orange3，代码行数:11，代码来源:util.py
示例3: test_mean_variance_axis1
def test_mean_variance_axis1():
X, _ = make_classification(5, 4, random_state=0)
# Sparsify the array a little bit
X[0, 0] = 0
X[2, 1] = 0
X[4, 3] = 0
X_lil = sp.lil_matrix(X)
X_lil[1, 0] = 0
X[1, 0] = 0
assert_raises(TypeError, mean_variance_axis, X_lil, axis=1)
X_csr = sp.csr_matrix(X_lil)
X_csc = sp.csc_matrix(X_lil)
expected_dtypes = [(np.float32, np.float32),
(np.float64, np.float64),
(np.int32, np.float64),
(np.int64, np.float64)]
for input_dtype, output_dtype in expected_dtypes:
X_test = X.astype(input_dtype)
for X_sparse in (X_csr, X_csc):
X_sparse = X_sparse.astype(input_dtype)
X_means, X_vars = mean_variance_axis(X_sparse, axis=0)
assert_equal(X_means.dtype, output_dtype)
assert_equal(X_vars.dtype, output_dtype)
assert_array_almost_equal(X_means, np.mean(X_test, axis=0))
assert_array_almost_equal(X_vars, np.var(X_test, axis=0))
开发者ID:MartinThoma，项目名称:scikit-learn，代码行数:29，代码来源:test_sparsefuncs.py
示例4: test_scale_function_without_centering
def test_scale_function_without_centering():
rng = np.random.RandomState(42)
X = rng.randn(4, 5)
X[:, 0] = 0.0 # first feature is always of zero
X_csr = sparse.csr_matrix(X)
X_scaled = scale(X, with_mean=False)
assert_false(np.any(np.isnan(X_scaled)))
X_csr_scaled = scale(X_csr, with_mean=False)
assert_false(np.any(np.isnan(X_csr_scaled.data)))
# test csc has same outcome
X_csc_scaled = scale(X_csr.tocsc(), with_mean=False)
assert_array_almost_equal(X_scaled, X_csc_scaled.toarray())
# raises value error on axis != 0
assert_raises(ValueError, scale, X_csr, with_mean=False, axis=1)
assert_array_almost_equal(X_scaled.mean(axis=0),
[0., -0.01, 2.24, -0.35, -0.78], 2)
assert_array_almost_equal(X_scaled.std(axis=0), [0., 1., 1., 1., 1.])
# Check that X has not been copied
assert_true(X_scaled is not X)
X_csr_scaled_mean, X_csr_scaled_std = mean_variance_axis(X_csr_scaled, 0)
assert_array_almost_equal(X_csr_scaled_mean, X_scaled.mean(axis=0))
assert_array_almost_equal(X_csr_scaled_std, X_scaled.std(axis=0))
开发者ID:0x0all，项目名称:scikit-learn，代码行数:28，代码来源:test_data.py
示例5: fit
def fit(self, X, y=None):
"""Don't trust the documentation of this module!
Compute the mean and std to be used for later scaling.
Parameters
----------
X : array-like or CSR matrix with shape [n_samples, n_features]
The data used to compute the mean and standard deviation
used for later scaling along the features axis.
"""
X = check_array(X, copy=self.copy, accept_sparse="csc",
ensure_2d=False)
if warn_if_not_float(X, estimator=self):
# Costly conversion, but otherwise the pipeline will break:
# https://github.com/scikit-learn/scikit-learn/issues/1709
X = X.astype(np.float32)
if sparse.issparse(X):
if self.center_sparse:
means = []
vars = []
# This only works for csc matrices...
for i in range(X.shape[1]):
if X.indptr[i] == X.indptr[i + 1]:
means.append(0)
vars.append(1)
else:
vars.append(
X.data[X.indptr[i]:X.indptr[i + 1]].var())
# If the variance is 0, set all occurences of this
# features to 1
means.append(
X.data[X.indptr[i]:X.indptr[i + 1]].mean())
if 0.0000001 >= vars[-1] >= -0.0000001:
means[-1] -= 1
self.std_ = np.sqrt(np.array(vars))
self.std_[np.array(vars) == 0.0] = 1.0
self.mean_ = np.array(means)
return self
elif self.with_mean:
raise ValueError(
"Cannot center sparse matrices: pass `with_mean=False` "
"instead. See docstring for motivation and alternatives.")
else:
self.mean_ = None
if self.with_std:
var = mean_variance_axis(X, axis=0)[1]
self.std_ = np.sqrt(var)
self.std_[var == 0.0] = 1.0
else:
self.std_ = None
return self
else:
self.mean_, self.std_ = _mean_and_std(
X, axis=0, with_mean=self.with_mean, with_std=self.with_std)
return self
开发者ID:Ayaro，项目名称:auto-sklearn，代码行数:60，代码来源:StandardScaler.py
示例6: test_scaler_without_centering
def test_scaler_without_centering():
rng = np.random.RandomState(42)
X = rng.randn(4, 5)
X[:, 0] = 0.0 # first feature is always of zero
X_csr = sparse.csr_matrix(X)
X_csc = sparse.csc_matrix(X)
assert_raises(ValueError, StandardScaler().fit, X_csr)
null_transform = StandardScaler(with_mean=False, with_std=False, copy=True)
X_null = null_transform.fit_transform(X_csr)
assert_array_equal(X_null.data, X_csr.data)
X_orig = null_transform.inverse_transform(X_null)
assert_array_equal(X_orig.data, X_csr.data)
scaler = StandardScaler(with_mean=False).fit(X)
X_scaled = scaler.transform(X, copy=True)
assert_false(np.any(np.isnan(X_scaled)))
scaler_csr = StandardScaler(with_mean=False).fit(X_csr)
X_csr_scaled = scaler_csr.transform(X_csr, copy=True)
assert_false(np.any(np.isnan(X_csr_scaled.data)))
scaler_csc = StandardScaler(with_mean=False).fit(X_csc)
X_csc_scaled = scaler_csr.transform(X_csc, copy=True)
assert_false(np.any(np.isnan(X_csc_scaled.data)))
assert_equal(scaler.mean_, scaler_csr.mean_)
assert_array_almost_equal(scaler.std_, scaler_csr.std_)
assert_equal(scaler.mean_, scaler_csc.mean_)
assert_array_almost_equal(scaler.std_, scaler_csc.std_)
assert_array_almost_equal(
X_scaled.mean(axis=0), [0., -0.01, 2.24, -0.35, -0.78], 2)
assert_array_almost_equal(X_scaled.std(axis=0), [0., 1., 1., 1., 1.])
X_csr_scaled_mean, X_csr_scaled_std = mean_variance_axis(X_csr_scaled, 0)
assert_array_almost_equal(X_csr_scaled_mean, X_scaled.mean(axis=0))
assert_array_almost_equal(X_csr_scaled_std, X_scaled.std(axis=0))
# Check that X has not been modified (copy)
assert_true(X_scaled is not X)
assert_true(X_csr_scaled is not X_csr)
X_scaled_back = scaler.inverse_transform(X_scaled)
assert_true(X_scaled_back is not X)
assert_true(X_scaled_back is not X_scaled)
assert_array_almost_equal(X_scaled_back, X)
X_csr_scaled_back = scaler_csr.inverse_transform(X_csr_scaled)
assert_true(X_csr_scaled_back is not X_csr)
assert_true(X_csr_scaled_back is not X_csr_scaled)
assert_array_almost_equal(X_csr_scaled_back.toarray(), X)
X_csc_scaled_back = scaler_csr.inverse_transform(X_csc_scaled.tocsc())
assert_true(X_csc_scaled_back is not X_csc)
assert_true(X_csc_scaled_back is not X_csc_scaled)
assert_array_almost_equal(X_csc_scaled_back.toarray(), X)
开发者ID:0x0all，项目名称:scikit-learn，代码行数:59，代码来源:test_data.py
示例7: mapper
def mapper(X):
"""Calculate statistics for every numpy or scipy blocks."""
X = check_array(X, ('csr', 'csc'), dtype=np.float64)
if hasattr(X, "toarray"): # sparse matrix
mean, var = mean_variance_axis(X, axis=0)
else:
mean, var = np.mean(X, axis=0), np.var(X, axis=0)
return X.shape[0], mean, var
开发者ID:JaysonSunshine，项目名称:sparkit-learn，代码行数:8，代码来源:variance_threshold.py
示例8: fit
def fit(self, X, y=None):
"""Learn empirical variances from X.
Parameters
----------
X : {array-like, sparse matrix}, shape (n_samples, n_features)
Sample vectors from which to compute variances.
y : any
Ignored. This parameter exists only for compatibility with
sklearn.pipeline.Pipeline.
Returns
-------
self
"""
X = check_array(X, ('csr', 'csc'), dtype=np.float64)
if hasattr(X, "toarray"): # sparse matrix
_, self.variances_ = mean_variance_axis(X, axis=0)
else:
self.variances_ = np.var(X, axis=0)
return self
开发者ID:m-guggenmos，项目名称:decog，代码行数:24，代码来源:feature_selection.py
示例9: test_incr_mean_variance_axis
def test_incr_mean_variance_axis():
for axis in [0, 1]:
rng = np.random.RandomState(0)
n_features = 50
n_samples = 10
data_chunks = [rng.randint(0, 2, size=n_features)
for i in range(n_samples)]
# default params for incr_mean_variance
last_mean = np.zeros(n_features)
last_var = np.zeros_like(last_mean)
last_n = np.zeros_like(last_mean, dtype=np.int64)
# Test errors
X = np.array(data_chunks[0])
X = np.atleast_2d(X)
X_lil = sp.lil_matrix(X)
X_csr = sp.csr_matrix(X_lil)
assert_raises(TypeError, incr_mean_variance_axis, axis,
last_mean, last_var, last_n)
assert_raises(TypeError, incr_mean_variance_axis, axis,
last_mean, last_var, last_n)
assert_raises(TypeError, incr_mean_variance_axis, X_lil, axis,
last_mean, last_var, last_n)
# Test _incr_mean_and_var with a 1 row input
X_means, X_vars = mean_variance_axis(X_csr, axis)
X_means_incr, X_vars_incr, n_incr = \
incr_mean_variance_axis(X_csr, axis, last_mean, last_var, last_n)
assert_array_almost_equal(X_means, X_means_incr)
assert_array_almost_equal(X_vars, X_vars_incr)
assert_equal(X.shape[axis], n_incr) # X.shape[axis] picks # samples
X_csc = sp.csc_matrix(X_lil)
X_means, X_vars = mean_variance_axis(X_csc, axis)
assert_array_almost_equal(X_means, X_means_incr)
assert_array_almost_equal(X_vars, X_vars_incr)
assert_equal(X.shape[axis], n_incr)
# Test _incremental_mean_and_var with whole data
X = np.vstack(data_chunks)
X_lil = sp.lil_matrix(X)
X_csr = sp.csr_matrix(X_lil)
X_csc = sp.csc_matrix(X_lil)
expected_dtypes = [(np.float32, np.float32),
(np.float64, np.float64),
(np.int32, np.float64),
(np.int64, np.float64)]
for input_dtype, output_dtype in expected_dtypes:
for X_sparse in (X_csr, X_csc):
X_sparse = X_sparse.astype(input_dtype)
last_mean = last_mean.astype(output_dtype)
last_var = last_var.astype(output_dtype)
X_means, X_vars = mean_variance_axis(X_sparse, axis)
X_means_incr, X_vars_incr, n_incr = \
incr_mean_variance_axis(X_sparse, axis, last_mean,
last_var, last_n)
assert_equal(X_means_incr.dtype, output_dtype)
assert_equal(X_vars_incr.dtype, output_dtype)
assert_array_almost_equal(X_means, X_means_incr)
assert_array_almost_equal(X_vars, X_vars_incr)
assert_equal(X.shape[axis], n_incr)
开发者ID:MartinThoma，项目名称:scikit-learn，代码行数:64，代码来源:test_sparsefuncs.py
示例10: test_scaler_int
def test_scaler_int():
# test that scaler converts integer input to floating
# for both sparse and dense matrices
rng = np.random.RandomState(42)
X = rng.randint(20, size=(4, 5))
X[:, 0] = 0 # first feature is always of zero
X_csr = sparse.csr_matrix(X)
X_csc = sparse.csc_matrix(X)
null_transform = StandardScaler(with_mean=False, with_std=False, copy=True)
clean_warning_registry()
with warnings.catch_warnings(record=True):
X_null = null_transform.fit_transform(X_csr)
assert_array_equal(X_null.data, X_csr.data)
X_orig = null_transform.inverse_transform(X_null)
assert_array_equal(X_orig.data, X_csr.data)
clean_warning_registry()
with warnings.catch_warnings(record=True):
scaler = StandardScaler(with_mean=False).fit(X)
X_scaled = scaler.transform(X, copy=True)
assert_false(np.any(np.isnan(X_scaled)))
clean_warning_registry()
with warnings.catch_warnings(record=True):
scaler_csr = StandardScaler(with_mean=False).fit(X_csr)
X_csr_scaled = scaler_csr.transform(X_csr, copy=True)
assert_false(np.any(np.isnan(X_csr_scaled.data)))
clean_warning_registry()
with warnings.catch_warnings(record=True):
scaler_csc = StandardScaler(with_mean=False).fit(X_csc)
X_csc_scaled = scaler_csr.transform(X_csc, copy=True)
assert_false(np.any(np.isnan(X_csc_scaled.data)))
assert_equal(scaler.mean_, scaler_csr.mean_)
assert_array_almost_equal(scaler.std_, scaler_csr.std_)
assert_equal(scaler.mean_, scaler_csc.mean_)
assert_array_almost_equal(scaler.std_, scaler_csc.std_)
assert_array_almost_equal(
X_scaled.mean(axis=0),
[0., 1.109, 1.856, 21., 1.559], 2)
assert_array_almost_equal(X_scaled.std(axis=0), [0., 1., 1., 1., 1.])
X_csr_scaled_mean, X_csr_scaled_std = mean_variance_axis(
X_csr_scaled.astype(np.float), 0)
assert_array_almost_equal(X_csr_scaled_mean, X_scaled.mean(axis=0))
assert_array_almost_equal(X_csr_scaled_std, X_scaled.std(axis=0))
# Check that X has not been modified (copy)
assert_true(X_scaled is not X)
assert_true(X_csr_scaled is not X_csr)
X_scaled_back = scaler.inverse_transform(X_scaled)
assert_true(X_scaled_back is not X)
assert_true(X_scaled_back is not X_scaled)
assert_array_almost_equal(X_scaled_back, X)
X_csr_scaled_back = scaler_csr.inverse_transform(X_csr_scaled)
assert_true(X_csr_scaled_back is not X_csr)
assert_true(X_csr_scaled_back is not X_csr_scaled)
assert_array_almost_equal(X_csr_scaled_back.toarray(), X)
X_csc_scaled_back = scaler_csr.inverse_transform(X_csc_scaled.tocsc())
assert_true(X_csc_scaled_back is not X_csc)
assert_true(X_csc_scaled_back is not X_csc_scaled)
assert_array_almost_equal(X_csc_scaled_back.toarray(), X)
开发者ID:0x0all，项目名称:scikit-learn，代码行数:69，代码来源:test_data.py
示例11: test_incr_mean_variance_axis
def test_incr_mean_variance_axis():
for axis in [0, 1]:
rng = np.random.RandomState(0)
n_features = 50
n_samples = 10
data_chunks = [rng.random_integers(0, 1, size=n_features)
for i in range(n_samples)]
# default params for incr_mean_variance
last_mean = np.zeros(n_features)
last_var = np.zeros_like(last_mean)
last_n = 0
# Test errors
X = np.array(data_chunks[0])
X = np.atleast_2d(X)
X_lil = sp.lil_matrix(X)
X_csr = sp.csr_matrix(X_lil)
assert_raises(TypeError, incr_mean_variance_axis, axis,
last_mean, last_var, last_n)
assert_raises(TypeError, incr_mean_variance_axis, axis,
last_mean, last_var, last_n)
assert_raises(TypeError, incr_mean_variance_axis, X_lil, axis,
last_mean, last_var, last_n)
# Test _incr_mean_and_var with a 1 row input
X_means, X_vars = mean_variance_axis(X_csr, axis)
X_means_incr, X_vars_incr, n_incr = \
incr_mean_variance_axis(X_csr, axis, last_mean, last_var, last_n)
assert_array_almost_equal(X_means, X_means_incr)
assert_array_almost_equal(X_vars, X_vars_incr)
assert_equal(X.shape[axis], n_incr) # X.shape[axis] picks # samples
X_csc = sp.csc_matrix(X_lil)
X_means, X_vars = mean_variance_axis(X_csc, axis)
assert_array_almost_equal(X_means, X_means_incr)
assert_array_almost_equal(X_vars, X_vars_incr)
assert_equal(X.shape[axis], n_incr)
# Test _incremental_mean_and_var with whole data
X = np.vstack(data_chunks)
X_lil = sp.lil_matrix(X)
X_csr = sp.csr_matrix(X_lil)
X_means, X_vars = mean_variance_axis(X_csr, axis)
X_means_incr, X_vars_incr, n_incr = \
incr_mean_variance_axis(X_csr, axis, last_mean, last_var, last_n)
assert_array_almost_equal(X_means, X_means_incr)
assert_array_almost_equal(X_vars, X_vars_incr)
assert_equal(X.shape[axis], n_incr)
X_csc = sp.csc_matrix(X_lil)
X_means, X_vars = mean_variance_axis(X_csc, axis)
assert_array_almost_equal(X_means, X_means_incr)
assert_array_almost_equal(X_vars, X_vars_incr)
assert_equal(X.shape[axis], n_incr)
# All data but as float
X = X.astype(np.float32)
X_csr = X_csr.astype(np.float32)
X_means, X_vars = mean_variance_axis(X_csr, axis)
X_means_incr, X_vars_incr, n_incr = \
incr_mean_variance_axis(X_csr, axis, last_mean, last_var, last_n)
assert_array_almost_equal(X_means, X_means_incr)
assert_array_almost_equal(X_vars, X_vars_incr)
assert_equal(X.shape[axis], n_incr)
X_csc = X_csr.astype(np.float32)
X_means, X_vars = mean_variance_axis(X_csc, axis)
assert_array_almost_equal(X_means, X_means_incr)
assert_array_almost_equal(X_vars, X_vars_incr)
assert_equal(X.shape[axis], n_incr)
开发者ID:Ablat，项目名称:scikit-learn，代码行数:71，代码来源:test_sparsefuncs.py
注：本文中的sklearn.utils.sparsefuncs.mean_variance_axis函数示例由纯净天空整理自Github/MSDocs等源码及文档管理平台，相关代码片段筛选自各路编程大神贡献的开源项目，源码版权归原作者所有，传播和使用请参考对应项目的License；未经允许，请勿转载。 |
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