scikit-learn/scikits/learn/utils/fixes.py

126 lines
3.4 KiB
Python

"""
Fixes for older version of numpy and scipy.
"""
# Authors: Emmanuelle Gouillart <emmanuelle.gouillart@normalesup.org>
# Gael Varoquaux <gael.varoquaux@normalesup.org>
# Fabian Pedregosa <fpedregosa@acm.org>
# License: BSD
import numpy as np
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.asanyarray(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 = np.__version__.split('.')
if int(np_version[0]) < 2 and int(np_version[1]) < 5:
unique = _unique
else:
unique = np.unique
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):
"""
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:
return scipy.linalg.qr(A, econ=True, **kwargs)
def arpack_eigsh(A, **kwargs):
"""
Scipy 0.9 renamed eigen_symmetric to eigsh in
scipy.sparse.linalg.eigen.arpack
"""
from scipy.sparse.linalg.eigen import arpack
if hasattr(arpack, 'eigsh'):
return arpack.eigsh(A, **kwargs)
else:
return arpack.eigen_symmetric(A, **kwargs)