Using PhysicalQuantities in IPython¶
The IPython extension makes using physical quantities easier. To load the extension use:
>>> %load_ext PhysicalQuantities.ipython
Now entering a physical quantities gets very easy:
>>> d = 2.3 s**3
>>> print("d = %s" %d)
d = 2.3 s^3
>>> t = 3 A
>>> print("t = %s" %t)
t = 3 A
>>> v = 2.3e3 * d / t
>>> print("v = %s" %v)
v = 1763.3333333333333 s^3/A
Unit conversion¶
The easiest way to scale a unit is to use prefix attributes:
>>> u = 1 V
>>> print(u)
1 V
>>> print(u.mV)
1000.0 mV
>>> print(u.uV)
1000000.0 uV
To convert between different representations of a unit, to()
can be
used:
>>> a = 1 N * 1 m
>>> print(a)
1 m*N
>>> print(a.to('J'))
1.0 J
Using other value types¶
The PhysicalQuantity
class tries to be a wrapper around the value of
a given quantity, i.e. not only single numbers can be used. For examples
using Numpy arrays, take a look at the Using Numpy
Arrays notebook.
>>> u = (1 + 1j) * 1V
>>> print("u = %s" %u)
u = (1+1j) V
>>> u = [1,2,3] * 1V
>>> print("u = %s" %u)
u = [1, 2, 3] V
>>> a = [1, 2, 3] * 1V
>>> a
\([1, 2, 3] $\text{V}\)
>>> a.value
[1, 2, 3]
>>> 2*a
\([1, 2, 3, 1, 2, 3] \text{V}\)
List of all defined Units:¶
All predefined units can be listed using the list()
or
html_list()
function of a unit:
>>> from PhysicalQuantities import units_html_list
>>> units_html_list()
Name | Base Unit | Quantity |
---|---|---|
Wb | 1.0 $\frac{\text{m}^{2}\cdot \text{kg}}{\text{A}\cdot \text{s}^2}$ | Weber |
s | 1.0 $\text{s}$ | Second |
h | 3600.0 $\text{s}$ | Hour |
lx | 1.0 $\frac{\text{cd}\cdot \text{sr}}{\text{m}^2}$ | Lux |
sr | 1.0 $\text{sr}$ | Streradian |
min | 60.0 $\text{s}$ | Minute |
J | 1.0 $\frac{\text{m}^{2}\cdot \text{kg}}{\text{s}^2}$ | Joule |
Pa | 1.0 $\frac{\text{kg}}{\text{m}\cdot \text{s}^2}$ | Pascal |
arcsec | 4.84813681109536e-06 $\text{rad}$ | seconds of arc |
cd | 1.0 $\text{cd}$ | Candela |
lm | 1.0 $\text{cd}\cdot \text{sr}$ | Lumen |
H | 1.0 $\frac{\text{m}^{2}\cdot \text{kg}}{\text{A}^2\cdot \text{s}^2}$ | Henry |
m | 1.0 $\text{m}$ | Metre |
T | 1.0 $\frac{\text{kg}}{\text{A}\cdot \text{s}^2}$ | Tesla |
S | 1.0 $\frac{\text{A}^{2}\cdot \text{s}^{3}}{\text{m}^2\cdot \text{kg}}$ | Siemens |
C | 1.0 $\text{A}\cdot \text{s}$ | Coulomb |
deg | 0.017453292519943295 $\text{rad}$ | Degree |
K | 1.0 $\text{K}$ | Kelvin |
g | 0.001 $\text{kg}$ | Gram |
kg | 1 $\text{kg}$ | Kilogram |
F | 1.0 $\frac{\text{A}^{2}\cdot \text{s}^{4}}{\text{m}^2\cdot \text{kg}}$ | Farad |
W | 1.0 $\frac{\text{m}^{2}\cdot \text{kg}}{\text{s}^3}$ | Watt |
arcmin | 0.0002908882086657216 $\text{rad}$ | minutes of arc |
Hz | 1.0 $\frac{1}{\text{s}}$ | Hertz |
A | 1.0 $\text{A}$ | Ampere |
Ohm | 1.0 $\frac{\text{m}^{2}\cdot \text{kg}}{\text{A}^2\cdot \text{s}^3}$ | Ohm |
N | 1.0 $\frac{\text{m}\cdot \text{kg}}{\text{s}^2}$ | Newton |
V | 1.0 $\frac{\text{m}^{2}\cdot \text{kg}}{\text{A}\cdot \text{s}^3}$ | Volt |
rad | 1.0 $\text{rad}$ | Radian |
mol | 1.0 $\text{mol}$ | Mol |