330 lines
12 KiB
Python
330 lines
12 KiB
Python
# Copyright (c) 2007, Robert Coup <robert.coup@onetrackmind.co.nz>
|
|
# All rights reserved.
|
|
#
|
|
# Redistribution and use in source and binary forms, with or without modification,
|
|
# are permitted provided that the following conditions are met:
|
|
#
|
|
# 1. Redistributions of source code must retain the above copyright notice,
|
|
# this list of conditions and the following disclaimer.
|
|
#
|
|
# 2. Redistributions in binary form must reproduce the above copyright
|
|
# notice, this list of conditions and the following disclaimer in the
|
|
# documentation and/or other materials provided with the distribution.
|
|
#
|
|
# 3. Neither the name of Distance nor the names of its contributors may be used
|
|
# to endorse or promote products derived from this software without
|
|
# specific prior written permission.
|
|
#
|
|
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
|
|
# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
|
|
# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
|
|
# DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
|
|
# ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
|
|
# (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
|
|
# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
|
|
# ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
|
|
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
|
|
# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
#
|
|
"""
|
|
Distance and Area objects to allow for sensible and convienient calculation
|
|
and conversions.
|
|
|
|
Authors: Robert Coup, Justin Bronn
|
|
|
|
Inspired by GeoPy (http://exogen.case.edu/projects/geopy/)
|
|
and Geoff Biggs' PhD work on dimensioned units for robotics.
|
|
"""
|
|
__all__ = ['A', 'Area', 'D', 'Distance']
|
|
from decimal import Decimal
|
|
|
|
class MeasureBase(object):
|
|
def default_units(self, kwargs):
|
|
"""
|
|
Return the unit value and the the default units specified
|
|
from the given keyword arguments dictionary.
|
|
"""
|
|
val = 0.0
|
|
for unit, value in kwargs.iteritems():
|
|
if unit in self.UNITS:
|
|
val += self.UNITS[unit] * value
|
|
default_unit = unit
|
|
elif unit in self.ALIAS:
|
|
u = self.ALIAS[unit]
|
|
val += self.UNITS[u] * value
|
|
default_unit = u
|
|
else:
|
|
lower = unit.lower()
|
|
if lower in self.UNITS:
|
|
val += self.UNITS[lower] * value
|
|
default_unit = lower
|
|
elif lower in self.LALIAS:
|
|
u = self.LALIAS[lower]
|
|
val += self.UNITS[u] * value
|
|
default_unit = u
|
|
else:
|
|
raise AttributeError('Unknown unit type: %s' % unit)
|
|
return val, default_unit
|
|
|
|
@classmethod
|
|
def unit_attname(cls, unit_str):
|
|
"""
|
|
Retrieves the unit attribute name for the given unit string.
|
|
For example, if the given unit string is 'metre', 'm' would be returned.
|
|
An exception is raised if an attribute cannot be found.
|
|
"""
|
|
lower = unit_str.lower()
|
|
if unit_str in cls.UNITS:
|
|
return unit_str
|
|
elif lower in cls.UNITS:
|
|
return lower
|
|
elif lower in cls.LALIAS:
|
|
return cls.LALIAS[lower]
|
|
else:
|
|
raise Exception('Could not find a unit keyword associated with "%s"' % unit_str)
|
|
|
|
class Distance(MeasureBase):
|
|
UNITS = {
|
|
'chain' : 20.1168,
|
|
'chain_benoit' : 20.116782,
|
|
'chain_sears' : 20.1167645,
|
|
'british_chain_benoit' : 20.1167824944,
|
|
'british_chain_sears' : 20.1167651216,
|
|
'british_chain_sears_truncated' : 20.116756,
|
|
'cm' : 0.01,
|
|
'british_ft' : 0.304799471539,
|
|
'british_yd' : 0.914398414616,
|
|
'clarke_ft' : 0.3047972654,
|
|
'clarke_link' : 0.201166195164,
|
|
'fathom' : 1.8288,
|
|
'ft': 0.3048,
|
|
'german_m' : 1.0000135965,
|
|
'gold_coast_ft' : 0.304799710181508,
|
|
'indian_yd' : 0.914398530744,
|
|
'inch' : 0.0254,
|
|
'km': 1000.0,
|
|
'link' : 0.201168,
|
|
'link_benoit' : 0.20116782,
|
|
'link_sears' : 0.20116765,
|
|
'm': 1.0,
|
|
'mi': 1609.344,
|
|
'mm' : 0.001,
|
|
'nm': 1852.0,
|
|
'nm_uk' : 1853.184,
|
|
'rod' : 5.0292,
|
|
'sears_yd' : 0.91439841,
|
|
'survey_ft' : 0.304800609601,
|
|
'um' : 0.000001,
|
|
'yd': 0.9144,
|
|
}
|
|
|
|
# Unit aliases for `UNIT` terms encountered in Spatial Reference WKT.
|
|
ALIAS = {
|
|
'centimeter' : 'cm',
|
|
'foot' : 'ft',
|
|
'inches' : 'inch',
|
|
'kilometer' : 'km',
|
|
'kilometre' : 'km',
|
|
'meter' : 'm',
|
|
'metre' : 'm',
|
|
'micrometer' : 'um',
|
|
'micrometre' : 'um',
|
|
'millimeter' : 'mm',
|
|
'millimetre' : 'mm',
|
|
'mile' : 'mi',
|
|
'yard' : 'yd',
|
|
'British chain (Benoit 1895 B)' : 'british_chain_benoit',
|
|
'British chain (Sears 1922)' : 'british_chain_sears',
|
|
'British chain (Sears 1922 truncated)' : 'british_chain_sears_truncated',
|
|
'British foot (Sears 1922)' : 'british_ft',
|
|
'British foot' : 'british_ft',
|
|
'British yard (Sears 1922)' : 'british_yd',
|
|
'British yard' : 'british_yd',
|
|
"Clarke's Foot" : 'clarke_ft',
|
|
"Clarke's link" : 'clarke_link',
|
|
'Chain (Benoit)' : 'chain_benoit',
|
|
'Chain (Sears)' : 'chain_sears',
|
|
'Foot (International)' : 'ft',
|
|
'German legal metre' : 'german_m',
|
|
'Gold Coast foot' : 'gold_coast_ft',
|
|
'Indian yard' : 'indian_yd',
|
|
'Link (Benoit)': 'link_benoit',
|
|
'Link (Sears)': 'link_sears',
|
|
'Nautical Mile' : 'nm',
|
|
'Nautical Mile (UK)' : 'nm_uk',
|
|
'US survey foot' : 'survey_ft',
|
|
'U.S. Foot' : 'survey_ft',
|
|
'Yard (Indian)' : 'indian_yd',
|
|
'Yard (Sears)' : 'sears_yd'
|
|
}
|
|
LALIAS = dict([(k.lower(), v) for k, v in ALIAS.items()])
|
|
|
|
def __init__(self, default_unit=None, **kwargs):
|
|
# The base unit is in meters.
|
|
self.m, self._default_unit = self.default_units(kwargs)
|
|
if default_unit and isinstance(default_unit, str):
|
|
self._default_unit = default_unit
|
|
|
|
def __getattr__(self, name):
|
|
if name in self.UNITS:
|
|
return self.m / self.UNITS[name]
|
|
else:
|
|
raise AttributeError('Unknown unit type: %s' % name)
|
|
|
|
def __repr__(self):
|
|
return 'Distance(%s=%s)' % (self._default_unit, getattr(self, self._default_unit))
|
|
|
|
def __str__(self):
|
|
return '%s %s' % (getattr(self, self._default_unit), self._default_unit)
|
|
|
|
def __cmp__(self, other):
|
|
if isinstance(other, Distance):
|
|
return cmp(self.m, other.m)
|
|
else:
|
|
return NotImplemented
|
|
|
|
def __add__(self, other):
|
|
if isinstance(other, Distance):
|
|
return Distance(default_unit=self._default_unit, m=(self.m + other.m))
|
|
else:
|
|
raise TypeError('Distance must be added with Distance')
|
|
|
|
def __iadd__(self, other):
|
|
if isinstance(other, Distance):
|
|
self.m += other.m
|
|
return self
|
|
else:
|
|
raise TypeError('Distance must be added with Distance')
|
|
|
|
def __sub__(self, other):
|
|
if isinstance(other, Distance):
|
|
return Distance(default_unit=self._default_unit, m=(self.m - other.m))
|
|
else:
|
|
raise TypeError('Distance must be subtracted from Distance')
|
|
|
|
def __isub__(self, other):
|
|
if isinstance(other, Distance):
|
|
self.m -= other.m
|
|
return self
|
|
else:
|
|
raise TypeError('Distance must be subtracted from Distance')
|
|
|
|
def __mul__(self, other):
|
|
if isinstance(other, (int, float, long, Decimal)):
|
|
return Distance(default_unit=self._default_unit, m=(self.m * float(other)))
|
|
elif isinstance(other, Distance):
|
|
return Area(default_unit='sq_' + self._default_unit, sq_m=(self.m * other.m))
|
|
else:
|
|
raise TypeError('Distance must be multiplied with number or Distance')
|
|
|
|
def __imul__(self, other):
|
|
if isinstance(other, (int, float, long, Decimal)):
|
|
self.m *= float(other)
|
|
return self
|
|
else:
|
|
raise TypeError('Distance must be multiplied with number')
|
|
|
|
def __div__(self, other):
|
|
if isinstance(other, (int, float, long, Decimal)):
|
|
return Distance(default_unit=self._default_unit, m=(self.m / float(other)))
|
|
else:
|
|
raise TypeError('Distance must be divided with number')
|
|
|
|
def __idiv__(self, other):
|
|
if isinstance(other, (int, float, long, Decimal)):
|
|
self.m /= float(other)
|
|
return self
|
|
else:
|
|
raise TypeError('Distance must be divided with number')
|
|
|
|
def __nonzero__(self):
|
|
return bool(self.m)
|
|
|
|
class Area(MeasureBase):
|
|
# Getting the square units values and the alias dictionary.
|
|
UNITS = dict([('sq_%s' % k, v ** 2) for k, v in Distance.UNITS.items()])
|
|
ALIAS = dict([(k, 'sq_%s' % v) for k, v in Distance.ALIAS.items()])
|
|
LALIAS = dict([(k.lower(), v) for k, v in ALIAS.items()])
|
|
|
|
def __init__(self, default_unit=None, **kwargs):
|
|
self.sq_m, self._default_unit = self.default_units(kwargs)
|
|
if default_unit and isinstance(default_unit, str):
|
|
self._default_unit = default_unit
|
|
|
|
def __getattr__(self, name):
|
|
if name in self.UNITS:
|
|
return self.sq_m / self.UNITS[name]
|
|
else:
|
|
raise AttributeError('Unknown unit type: ' + name)
|
|
|
|
def __repr__(self):
|
|
return 'Area(%s=%s)' % (self._default_unit, getattr(self, self._default_unit))
|
|
|
|
def __str__(self):
|
|
return '%s %s' % (getattr(self, self._default_unit), self._default_unit)
|
|
|
|
def __cmp__(self, other):
|
|
if isinstance(other, Area):
|
|
return cmp(self.sq_m, other.sq_m)
|
|
else:
|
|
return NotImplemented
|
|
|
|
def __add__(self, other):
|
|
if isinstance(other, Area):
|
|
return Area(default_unit=self._default_unit, sq_m=(self.sq_m + other.sq_m))
|
|
else:
|
|
raise TypeError('Area must be added with Area')
|
|
|
|
def __iadd__(self, other):
|
|
if isinstance(other, Area):
|
|
self.sq_m += other.sq_m
|
|
return self
|
|
else:
|
|
raise TypeError('Area must be added with Area')
|
|
|
|
def __sub__(self, other):
|
|
if isinstance(other, Area):
|
|
return Area(default_unit=self._default_unit, sq_m=(self.sq_m - other.sq_m))
|
|
else:
|
|
raise TypeError('Area must be subtracted from Area')
|
|
|
|
def __isub__(self, other):
|
|
if isinstance(other, Area):
|
|
self.sq_m -= other.sq_m
|
|
return self
|
|
else:
|
|
raise TypeError('Area must be subtracted from Area')
|
|
|
|
def __mul__(self, other):
|
|
if isinstance(other, (int, float, long, Decimal)):
|
|
return Area(default_unit=self._default_unit, sq_m=(self.sq_m * float(other)))
|
|
else:
|
|
raise TypeError('Area must be multiplied with number')
|
|
|
|
def __imul__(self, other):
|
|
if isinstance(other, (int, float, long, Decimal)):
|
|
self.sq_m *= float(other)
|
|
return self
|
|
else:
|
|
raise TypeError('Area must be multiplied with number')
|
|
|
|
def __div__(self, other):
|
|
if isinstance(other, (int, float, long, Decimal)):
|
|
return Area(default_unit=self._default_unit, sq_m=(self.sq_m / float(other)))
|
|
else:
|
|
raise TypeError('Area must be divided with number')
|
|
|
|
def __idiv__(self, other):
|
|
if isinstance(other, (int, float, long, Decimal)):
|
|
self.sq_m /= float(other)
|
|
return self
|
|
else:
|
|
raise TypeError('Area must be divided with number')
|
|
|
|
def __nonzero__(self):
|
|
return bool(self.sq_m)
|
|
|
|
# Shortcuts
|
|
D = Distance
|
|
A = Area
|