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 |