Opened 3 years ago

Last modified 3 years ago

## #20411 new enhancement

# Injecting shorthands for the most usual units

Reported by: | nthiery | Owned by: | |
---|---|---|---|

Priority: | major | Milestone: | sage-7.2 |

Component: | symbolics | Keywords: | |

Cc: | Merged in: | ||

Authors: | Reviewers: | ||

Report Upstream: | N/A | Work issues: | |

Branch: | Commit: | ||

Dependencies: | Stopgaps: |

### Description

Implement `inject_shorthands`

```
that would inject into the global name space shorthands for the most usual units::
```

sage: units.inject_shorthands() sage: 3 * kg * m / s^2 3*kilogram*meter/second^2

This can be implemented easily as in e.g. `sage.combinat.sf.sf.SymmetricFunctions?.inject_shorthands`

```
, together with a dictionary mapping shorthands to the corresponding units.
```

The main difficulty is to agree on a list of shorthands :-)

Let's start a list: s, mm, cm, m, km, g, kg, ...; Maybe l, W, J, ...; Maybe long names for the less usual units: ton, watt, ...

Or have something like:

sage: sage.units.mass.inject_shorthands(all=True)

that injects all the units with their long names.

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I think the easiest thing we could agree on is using the SI unit abbreviations. For non SI units, maybe use the long name to avoid ambiguity.

http://www.ewh.ieee.org/soc/ias/pub-dept/abbreviation.pdf