# UnitsΒΆ

WrightTools provides its own units system. You can use it directly, if you wish.

```
>>> import WrightTools as wt
>>> wt.units.converter(2., 'eV', 'nm')
620.0
```

This same units system enables the units-aware properties throughout WrightTools.

In WrightTools, units are organized into kinds. It is always possible to convert between units of the same kind, and never possible to convert between kinds.

The units system also provides a symbol for each unit, enabling easy plotting.

The following table contains every unit in WrightTools.

name | description | kind | symbol |

rad | radian | angle | None |

deg | degrees | angle | None |

fs | femtoseconds | delay | \(\tau\) |

ps | picoseconds | delay | \(\tau\) |

ns | nanoseconds | delay | \(\tau\) |

mm_delay | mm | delay | \(\tau\) |

nm | nanometers | energy | \(\lambda\) |

wn | wavenumbers | energy | \(\bar{\nu}\) |

eV | electronvolts | energy | \(\hslash\omega\) |

meV | millielectronvolts | energy | \(E\) |

Hz | hertz | energy | \(f\) |

THz | terahertz | energy | \(f\) |

GHz | gigahertz | energy | \(f\) |

K | kelvin | temperature | \(T\) |

deg_C | celsius | temperature | \(T\) |

deg_F | fahrenheit | temperature | \(T\) |

deg_R | rankine | temperature | \(T\) |

fluence | uJ per sq. cm | intensity | \(\mathcal{F}\) |

mOD | mOD | optical density | None |

OD | OD | optical density | None |

nm_p | nanometers | position | None |

um | microns | position | None |

mm | millimeters | position | None |

cm | centimeters | position | None |

in | inches | position | None |

FWHM | full width half max | pulse width | \(\sigma\) |

fs_t | femtoseconds | time | None |

ps_t | picoseconds | time | None |

ns_t | nanoseconds | time | None |

us_t | microseconds | time | None |

ms_t | milliseconds | time | None |

s_t | seconds | time | None |

m_t | minutes | time | None |

h_t | hours | time | None |

d_t | days | time | None |