scikit-learn/sklearn/utils/fixes.py

235 lines
6.9 KiB
Python

"""Compatibility fixes for older version of python, numpy and scipy
If you add content to this file, please give the version of the package
at which the fixe is no longer needed.
"""
# Authors: Emmanuelle Gouillart <emmanuelle.gouillart@normalesup.org>
# Gael Varoquaux <gael.varoquaux@normalesup.org>
# Fabian Pedregosa <fpedregosa@acm.org>
#
# License: BSD 3 clause
from operator import itemgetter
import inspect
from sklearn.externals import six
import numpy as np
def lsqr(X, y, tol=1e-3):
import scipy.sparse.linalg as sp_linalg
from ..utils.extmath import safe_sparse_dot
if hasattr(sp_linalg, 'lsqr'):
# scipy 0.8 or greater
return sp_linalg.lsqr(X, y)
else:
n_samples, n_features = X.shape
if n_samples > n_features:
coef, _ = sp_linalg.cg(safe_sparse_dot(X.T, X),
safe_sparse_dot(X.T, y),
tol=tol)
else:
coef, _ = sp_linalg.cg(safe_sparse_dot(X, X.T), y, tol=tol)
coef = safe_sparse_dot(X.T, coef)
residues = y - safe_sparse_dot(X, coef)
return coef, None, None, residues
def _unique(ar, return_index=False, return_inverse=False):
"""A replacement for the np.unique that appeared in numpy 1.4.
While np.unique existed long before, keyword return_inverse was
only added in 1.4.
"""
try:
ar = ar.flatten()
except AttributeError:
if not return_inverse and not return_index:
items = sorted(set(ar))
return np.asarray(items)
else:
ar = np.asarray(ar).flatten()
if ar.size == 0:
if return_inverse and return_index:
return ar, np.empty(0, np.bool), np.empty(0, np.bool)
elif return_inverse or return_index:
return ar, np.empty(0, np.bool)
else:
return ar
if return_inverse or return_index:
perm = ar.argsort()
aux = ar[perm]
flag = np.concatenate(([True], aux[1:] != aux[:-1]))
if return_inverse:
iflag = np.cumsum(flag) - 1
iperm = perm.argsort()
if return_index:
return aux[flag], perm[flag], iflag[iperm]
else:
return aux[flag], iflag[iperm]
else:
return aux[flag], perm[flag]
else:
ar.sort()
flag = np.concatenate(([True], ar[1:] != ar[:-1]))
return ar[flag]
np_version = []
for x in np.__version__.split('.'):
try:
np_version.append(int(x))
except ValueError:
# x may be of the form dev-1ea1592
np_version.append(x)
np_version = tuple(np_version)
if np_version[:2] < (1, 5):
unique = _unique
else:
unique = np.unique
def _logaddexp(x1, x2, out=None):
"""Fix np.logaddexp in numpy < 1.4 when x1 == x2 == -np.inf."""
if out is not None:
result = np.logaddexp(x1, x2, out=out)
else:
result = np.logaddexp(x1, x2)
result[np.logical_and(x1 == -np.inf, x2 == -np.inf)] = -np.inf
return result
if np_version[:2] < (1, 4):
logaddexp = _logaddexp
else:
logaddexp = np.logaddexp
def _bincount(X, weights=None, minlength=None):
"""Replacing np.bincount in numpy < 1.6 to provide minlength."""
result = np.bincount(X, weights)
if len(result) >= minlength:
return result
out = np.zeros(minlength, np.int)
out[:len(result)] = result
return out
if np_version[:2] < (1, 6):
bincount = _bincount
else:
bincount = np.bincount
def _copysign(x1, x2):
"""Slow replacement for np.copysign, which was introduced in numpy 1.4"""
return np.abs(x1) * np.sign(x2)
if not hasattr(np, 'copysign'):
copysign = _copysign
else:
copysign = np.copysign
def _in1d(ar1, ar2, assume_unique=False):
"""Replacement for in1d that is provided for numpy >= 1.4"""
if not assume_unique:
ar1, rev_idx = unique(ar1, return_inverse=True)
ar2 = np.unique(ar2)
ar = np.concatenate((ar1, ar2))
# We need this to be a stable sort, so always use 'mergesort'
# here. The values from the first array should always come before
# the values from the second array.
order = ar.argsort(kind='mergesort')
sar = ar[order]
equal_adj = (sar[1:] == sar[:-1])
flag = np.concatenate((equal_adj, [False]))
indx = order.argsort(kind='mergesort')[:len(ar1)]
if assume_unique:
return flag[indx]
else:
return flag[indx][rev_idx]
if not hasattr(np, 'in1d'):
in1d = _in1d
else:
in1d = np.in1d
def qr_economic(A, **kwargs):
"""Compat function for the QR-decomposition in economic mode
Scipy 0.9 changed the keyword econ=True to mode='economic'
"""
import scipy.linalg
# trick: triangular solve has introduced in 0.9
if hasattr(scipy.linalg, 'solve_triangular'):
return scipy.linalg.qr(A, mode='economic', **kwargs)
else:
import warnings
with warnings.catch_warnings():
warnings.simplefilter("ignore", DeprecationWarning)
return scipy.linalg.qr(A, econ=True, **kwargs)
def savemat(file_name, mdict, oned_as="column", **kwargs):
"""MATLAB-format output routine that is compatible with SciPy 0.7's.
0.7.2 (or .1?) added the oned_as keyword arg with 'column' as the default
value. It issues a warning if this is not provided, stating that "This will
change to 'row' in future versions."
"""
import scipy.io
try:
return scipy.io.savemat(file_name, mdict, oned_as=oned_as, **kwargs)
except TypeError:
return scipy.io.savemat(file_name, mdict, **kwargs)
try:
from numpy import count_nonzero
except ImportError:
def count_nonzero(X):
return len(np.flatnonzero(X))
# little danse to see if np.copy has an 'order' keyword argument
if 'order' in inspect.getargspec(np.copy)[0]:
def safe_copy(X):
# Copy, but keep the order
return np.copy(X, order='K')
else:
# Before an 'order' argument was introduced, numpy wouldn't muck with
# the ordering
safe_copy = np.copy
try:
if (not np.allclose(np.divide(.4, 1), np.divide(.4, 1, dtype=np.float))
or not np.allclose(np.divide(.4, 1), .4)):
raise TypeError('Divide not working with dtype: '
'https://github.com/numpy/numpy/issues/3484')
divide = np.divide
except TypeError:
# Compat for old versions of np.divide that do not provide support for
# the dtype args
def divide(x1, x2, out=None, dtype=None):
out_orig = out
if out is None:
out = np.asarray(x1, dtype=dtype)
if out is x1:
out = x1.copy()
else:
if out is not x1:
out[:] = x1
if dtype is not None and out.dtype != dtype:
out = out.astype(dtype)
out /= x2
if out_orig is None and np.isscalar(x1):
out = np.asscalar(out)
return out