laywerrobot/lib/python3.6/site-packages/scipy/linalg/flinalg.py

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2020-08-27 21:55:39 +02:00
#
# Author: Pearu Peterson, March 2002
#
from __future__ import division, print_function, absolute_import
__all__ = ['get_flinalg_funcs']
# The following ensures that possibly missing flavor (C or Fortran) is
# replaced with the available one. If none is available, exception
# is raised at the first attempt to use the resources.
try:
from . import _flinalg
except ImportError:
_flinalg = None
# from numpy.distutils.misc_util import PostponedException
# _flinalg = PostponedException()
# print _flinalg.__doc__
has_column_major_storage = lambda a:0
def has_column_major_storage(arr):
return arr.flags['FORTRAN']
_type_conv = {'f':'s', 'd':'d', 'F':'c', 'D':'z'} # 'd' will be default for 'i',..
def get_flinalg_funcs(names,arrays=(),debug=0):
"""Return optimal available _flinalg function objects with
names. arrays are used to determine optimal prefix."""
ordering = []
for i in range(len(arrays)):
t = arrays[i].dtype.char
if t not in _type_conv:
t = 'd'
ordering.append((t,i))
if ordering:
ordering.sort()
required_prefix = _type_conv[ordering[0][0]]
else:
required_prefix = 'd'
# Some routines may require special treatment.
# Handle them here before the default lookup.
# Default lookup:
if ordering and has_column_major_storage(arrays[ordering[0][1]]):
suffix1,suffix2 = '_c','_r'
else:
suffix1,suffix2 = '_r','_c'
funcs = []
for name in names:
func_name = required_prefix + name
func = getattr(_flinalg,func_name+suffix1,
getattr(_flinalg,func_name+suffix2,None))
funcs.append(func)
return tuple(funcs)