/usr/lib/python2.7/dist-packages/ffc/uflacs/analysis/crsarray.py is in python-ffc 2016.2.0-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 | # -*- coding: utf-8 -*-
# Copyright (C) 2011-2016 Martin Sandve Alnæs
#
# This file is part of UFLACS.
#
# UFLACS is free software: you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# UFLACS is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with UFLACS. If not, see <http://www.gnu.org/licenses/>
"""Compressed row storage 'matrix' (actually just a non-rectangular 2d array)."""
import numpy
class CRSArray(object):
"""An array of variable length dense arrays.
Stored efficiently with simple compressed row storage.
This CRS array variant doesn't have a sparsity pattern,
as each row is simply a dense vector.
Values are stored in one flat array 'data[]',
and 'row_offsets[i]' contains the index to the first
element on row i for 0<=i<=num_rows.
There is no column index.
"""
def __init__(self, row_capacity, element_capacity, dtype):
itype = numpy.int16 if row_capacity < 2**15 else numpy.int32
self.row_offsets = numpy.zeros(row_capacity + 1, dtype=itype)
self.data = numpy.zeros(element_capacity, dtype=dtype)
self.num_rows = 0
def push_row(self, elements):
a = self.row_offsets[self.num_rows]
b = a + len(elements)
self.data[a:b] = elements
self.num_rows += 1
self.row_offsets[self.num_rows] = b
@property
def num_elements(self):
return self.row_offsets[self.num_rows]
def __getitem__(self, row):
if row < 0 or row >= self.num_rows:
raise IndexError("Row number out of range!")
a = self.row_offsets[row]
b = self.row_offsets[row + 1]
return self.data[a:b]
def __len__(self):
return self.num_rows
def __str__(self):
return "[%s]" % ('\n'.join(str(row) for row in self),)
@classmethod
def from_rows(cls, rows, num_rows, num_elements, dtype):
"Construct a CRSArray from a list of row element lists."
crs = CRSArray(num_rows, num_elements, dtype)
for row in rows:
crs.push_row(row)
return crs
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