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import os, re
curdir, _ = os.path.split(__file__)
units_fname = os.path.normpath(os.path.join(curdir, '../../../brian2/units/allunits.py'))
_siprefixes = {"y":1e-24, "z":1e-21, "a":1e-18, "f":1e-15, "p":1e-12, "n":1e-9,
"u":1e-6, "m":1e-3, "c":1e-2, "d":1e-1, "":1, "da":1e1, "h":1e2,
"k":1e3, "M":1e6, "G":1e9, "T":1e12, "P":1e15, "E":1e18,
"Z":1e21, "Y":1e24}
fundamental_units = ['metre', 'meter', 'kilogram', 'second', 'amp', 'ampere', 'kelvin', 'mole', 'mol', 'candle']
#### DERIVED UNITS, from http://physics.nist.gov/cuu/Units/units.html
derived_unit_table = [
['radian', 'rad', 'get_or_create_dimension()'],
['steradian', 'sr', 'get_or_create_dimension()'],
['hertz', 'Hz', 'get_or_create_dimension(s= -1)'],
['newton', 'N', 'get_or_create_dimension(m=1, kg=1, s=-2)'],
['pascal', 'Pa', 'get_or_create_dimension(m= -1, kg=1, s=-2)'],
['joule', 'J', 'get_or_create_dimension(m=2, kg=1, s=-2)'],
['watt', 'W', 'get_or_create_dimension(m=2, kg=1, s=-3)'],
['coulomb', 'C', 'get_or_create_dimension(s=1, A=1)'],
['volt', 'V', 'get_or_create_dimension(m=2, kg=1, s=-3, A=-1)'],
['farad', 'F', 'get_or_create_dimension(m= -2, kg=-1, s=4, A=2)'],
['ohm', 'ohm', 'get_or_create_dimension(m=2, kg=1, s= -3, A=-2)'],
['siemens', 'S', 'get_or_create_dimension(m= -2, kg=-1, s=3, A=2)'],
['weber', 'Wb', 'get_or_create_dimension(m=2, kg=1, s=-2, A=-1)'],
['tesla', 'T', 'get_or_create_dimension(kg=1, s=-2, A=-1)'],
['henry', 'H', 'get_or_create_dimension(m=2, kg=1, s=-2, A=-2)'],
['lumen', 'lm', 'get_or_create_dimension(cd=1)'],
['lux', 'lx', 'get_or_create_dimension(m=-2, cd=1)'],
['becquerel', 'Bq', 'get_or_create_dimension(s=-1)'],
['gray', 'Gy', 'get_or_create_dimension(m=2, s=-2)'],
['sievert', 'Sv', 'get_or_create_dimension(m=2, s=-2)'],
['katal', 'kat', 'get_or_create_dimension(s=-1, mol=1)'],
]
## Generate derived unit objects and make a table of base units from these and the fundamental ones
base_units = fundamental_units+['kilogramme', 'gram', 'gramme', 'molar']
derived = ''
for longname, shortname, definition in derived_unit_table:
derived += '{longname} = Unit.create({definition}, "{longname}", "{shortname}")\n'.format(
longname=longname, shortname=shortname, definition=definition)
base_units.append(longname)
all_units = base_units + []
definitions = '######### SCALED BASE UNITS ###########\n'
# Generate scaled units for all base units
scaled_units = []
excluded_scaled_units = set()
for _bu in base_units:
if _bu in ['kelvin', 'kilogram', 'kilogramme']:
continue # do not create "mkelvin", "kkilogram" etc.
for _k in _siprefixes.keys():
if len(_k):
_u = _k+_bu
all_units.append(_u)
definitions += '{_u} = Unit.create_scaled_unit({_bu}, "{_k}")\n'.format(
_u=_u, _bu=_bu, _k=_k)
if _k not in ["da", "d", "c", "h"]:
scaled_units.append(_u)
else:
excluded_scaled_units.add(_u)
# Generate 2nd and 3rd powers for all scaled base units
definitions += '######### SCALED BASE UNITS TO POWERS ###########\n'
powered_units = []
for bu in all_units + []:
for i in [2, 3]:
u = bu+str(i)
definitions += '{u} = Unit.create(({bu}**{i}).dim, name="{u}", ' \
'dispname=str({bu})+"^{i}", ' \
'scale={bu}.scale*{i})\n'.format(u=u, bu=bu, i=i)
all_units.append(u)
if bu not in excluded_scaled_units:
powered_units.append(u)
additional_units = '''
# Current list from http://physics.nist.gov/cuu/Units/units.html, far from complete
additional_units = [
pascal * second, newton * metre, watt / metre ** 2, joule / kelvin,
joule / (kilogram * kelvin), joule / kilogram, watt / (metre * kelvin),
joule / metre ** 3, volt / metre ** 3, coulomb / metre ** 3, coulomb / metre ** 2,
farad / metre, henry / metre, joule / mole, joule / (mole * kelvin),
coulomb / kilogram, gray / second, katal / metre ** 3,
# We don't want liter/litre to be used as a standard unit for display, so we
# put it here instead of in the standard units
'''
# Scaled units for liter (we don't want liter**2, etc., so it is not included
# in the base units above; also, we don't want it to register in the standard
# units, so it is not chosen instead of meter**3 for displaying volume
# quantities)
for _bu in ['liter', 'litre']:
all_units.append(_bu)
for _k in _siprefixes.keys():
_u = _k + _bu
all_units.append(_u)
definitions += '{_u} = Unit.create_scaled_unit({_bu}, "{_k}")\n'.format(
_u=_u, _bu=_bu, _k=_k)
additional_units += _u + ', '
additional_units += ']'
# Add unit names to __all__
all = '''
__all__ = [
{allunits}
"celsius" # Dummy object raising an error
]
'''.format(allunits='\n'.join(' "'+u+'",' for u in all_units))
def to_definition(name, x):
return '''
{name} = [
{items}
]
'''.format(name=name, items='\n'.join(' '+i+',' for i in x))
# Note that for presentation purposes, the `UnitRegistry` uses the *last*
# defined unit for a given scale. Therefore, we reserve the order of the units
# so that the standard units come first.
with open('units_template.py') as f:
template = f.read()
units_str = template.format(
derived=derived, all=all, definitions=definitions,
base_units=to_definition('base_units', base_units[::-1]),
scaled_units=to_definition('scaled_units', scaled_units[::-1]),
powered_units=to_definition('powered_units', powered_units[::-1]),
all_units=to_definition('all_units', all_units[::-1]),
additional_units=additional_units,
)
with open(units_fname, 'w') as f:
f.write(units_str)
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