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Diffstat (limited to 'silx/utils/number.py')
| -rw-r--r-- | silx/utils/number.py | 143 |
1 files changed, 0 insertions, 143 deletions
diff --git a/silx/utils/number.py b/silx/utils/number.py deleted file mode 100644 index 92e98fe..0000000 --- a/silx/utils/number.py +++ /dev/null @@ -1,143 +0,0 @@ -# coding: utf-8 -# /*########################################################################## -# -# Copyright (c) 2016-2018 European Synchrotron Radiation Facility -# -# Permission is hereby granted, free of charge, to any person obtaining a copy -# of this software and associated documentation files (the "Software"), to deal -# in the Software without restriction, including without limitation the rights -# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell -# copies of the Software, and to permit persons to whom the Software is -# furnished to do so, subject to the following conditions: -# -# The above copyright notice and this permission notice shall be included in -# all copies or substantial portions of the Software. -# -# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR -# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, -# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE -# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER -# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, -# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN -# THE SOFTWARE. -# -# ###########################################################################*/ -"""Utilitary functions dealing with numbers. -""" - -__authors__ = ["V. Valls"] -__license__ = "MIT" -__date__ = "05/06/2018" - -import numpy -import re -import logging - - -_logger = logging.getLogger(__name__) - - -_biggest_float = None - -if hasattr(numpy, "longdouble"): - finfo = numpy.finfo(numpy.longdouble) - # The bit for sign is missing here - bits = finfo.nexp + finfo.nmant - if bits > 64: - _biggest_float = numpy.longdouble - # From bigger to smaller - _float_types = (numpy.longdouble, numpy.float64, numpy.float32, numpy.float16) -if _biggest_float is None: - _biggest_float = numpy.float64 - # From bigger to smaller - _float_types = (numpy.float64, numpy.float32, numpy.float16) - - -_parse_numeric_value = re.compile(r"^\s*[-+]?0*(\d+?)?(?:\.(\d+))?(?:[eE]([-+]?\d+))?\s*$") - - -def is_longdouble_64bits(): - """Returns true if the system uses floating-point 64bits for it's - long double type. - - .. note:: Comparing `numpy.longdouble` and `numpy.float64` on Windows is not - possible (or at least not will all the numpy version) - """ - return _biggest_float == numpy.float64 - - -def min_numerical_convertible_type(string, check_accuracy=True): - """ - Parse the string and return the smallest numerical type to use for a safe - conversion. - - :param str string: Representation of a float/integer with text - :param bool check_accuracy: If true, a warning is pushed on the logger - in case there is a loss of accuracy. - :raise ValueError: When the string is not a numerical value - :retrun: A numpy numerical type - """ - if string == "": - raise ValueError("Not a numerical value") - match = _parse_numeric_value.match(string) - if match is None: - raise ValueError("Not a numerical value") - number, decimal, exponent = match.groups() - - if decimal is None and exponent is None: - # It's an integer - # TODO: We could find the int type without converting the number - value = int(string) - return numpy.min_scalar_type(value).type - - # Try floating-point - try: - value = _biggest_float(string) - except ValueError: - raise ValueError("Not a numerical value") - - if number is None: - number = "" - if decimal is None: - decimal = "" - if exponent is None: - exponent = "0" - - nb_precision_digits = int(exponent) - len(decimal) - 1 - precision = _biggest_float(10) ** nb_precision_digits * 2.5 - previous_type = _biggest_float - for numpy_type in _float_types: - if numpy_type == _biggest_float: - # value was already casted using the bigger type - continue - reduced_value = numpy_type(value) - if not numpy.isfinite(reduced_value): - break - # numpy isclose(atol=is not accurate enough) - diff = value - reduced_value - # numpy 1.8.2 looks to do the substraction using float64... - # we lose precision here - diff = numpy.abs(diff) - if diff > precision: - break - previous_type = numpy_type - - # It's the smaller float type which fit with enougth precision - numpy_type = previous_type - - if check_accuracy and numpy_type == _biggest_float: - # Check the precision using the original string - expected = number + decimal - # This format the number without python convertion - try: - result = numpy.array2string(value, precision=len(number) + len(decimal), floatmode="fixed") - except TypeError: - # numpy 1.8.2 do not have floatmode argument - _logger.warning("Not able to check accuracy of the conversion of '%s' using %s", string, _biggest_float) - return numpy_type - - result = result.replace(".", "").replace("-", "") - if not result.startswith(expected): - _logger.warning("Not able to convert '%s' using %s without losing precision", string, _biggest_float) - - return numpy_type |