intec-units 0.0.5

Physical units library

Standard physical units are imported from intec.units.si

from intec.units.si import METER, MILLIMETER, NANOMETER, AMPERE, VOLT, OHM

A Quantity is created by multiplying a number (the magnitude) and a Unit

d = 1550*NANOMETER
print(d)

1550.000000 nm

d

LengthQuantity( 1.5500000000e+03, nm )

Quantities of the same physical dimension can be added or substracted

1*METER + 5*MILLIMETER

LengthQuantity( 1.0050000000e+00, m )

The resulting quantity gets the unit of the first term.

print(5*MILLIMETER + 1*METER)

1005.000000 mm

1*METER + 1*AMPERE

---------------------------------------------------------------------------

TypeError                                 Traceback (most recent call last)

<ipython-input-6-26114287a935> in <module>
----> 1 1*METER + 1*AMPERE


TypeError: Cannot convert unit [A] to unit [m]

Quantities of the same physical dimension can be compared

p = 1*VOLT*2*AMPERE
print(p)

2.000000 V.A

from intec.units.si import WATT, MILLIWATT, DBM
p == 2*WATT

True

3*VOLT/AMPERE > 2*OHM

True

Use the to member function to convert a quantity to a related unit.

print(p.to(MILLIWATT))
print(p.to(DBM))

2000.000000 mW
33.010300 dBm

from intec.units.si import METER, KILOMETER, SECOND
from intec.units.extra import HOUR
speed = 10*METER/SECOND
print(speed.to(KILOMETER/HOUR))

36.000000 km/h

Use the member magnitude or m to retrieve the numerical value of a quantity

speed.magnitude

10.0

speed.m

10.0

Use the member unit or u to retrieve the unit of a quantity

speed.unit

Unit( 'm/s' [m/s] )

speed.u

Unit( 'm/s' [m/s] )

For (wave)lengths there is a convenience function to convert to frequency.

from intec.units.si import NANOMETER,HERTZ
λ = 1550*NANOMETER
λ.to_frequency()

FrequencyQuantity( 1.9341448903e+02, THz )

λ.to_frequency(HERTZ)

FrequencyQuantity( 1.9341448903e+14, Hz )

For photonic experiments, use intec.units.photonic to import all common units in one fell swoop

from intec.units.photonic import *

from .si import METER, MILLIMETER, MICROMETER, NANOMETER, PICOMETER, FEMTOMETER
from .si import WATT, MILLIWATT, MICROWATT, DBM
from .si import VOLT, MILLIVOLT, MICROVOLT
from .si import AMPERE, MILLIAMPERE, MICROAMPERE
from .si import HERTZ, KILOHERTZ, MEGAHERTZ, GIGAHERTZ, TERAHERTZ
from .si import SECOND, MILLISECOND, MICROSECOND
from .si import KELVIN, CELCIUS