pint-compute

SKILL.md

Unit Computation with Pint

Cognitive prosthetics for unit-aware computation. Use Pint for converting between units, performing unit arithmetic, checking dimensional compatibility, and simplifying compound units.

When to Use

Converting between units (meters to feet, kg to pounds)

Unit-aware arithmetic (velocity x time = distance)

Dimensional analysis (is force = mass x acceleration?)

Simplifying compound units to base or named units

Parsing and analyzing quantities with units

Quick Reference

I want to...
Command
Example

Convert units
convert
convert "5 meters" --to feet

Unit math
calc
calc "10 m/s * 5 s"

Check dimensions
check
check newton --against "kg * m / s^2"

Parse quantity
parse
parse "100 km/h"

Simplify units
simplify
simplify "1 kg*m/s^2"

Commands

parse

Parse a quantity string into magnitude, units, and dimensionality.

uv run python -m runtime.harness scripts/pint_compute.py \
    parse "100 km/h"

uv run python -m runtime.harness scripts/pint_compute.py \
    parse "9.8 m/s^2"

convert

Convert a quantity to different units.

uv run python -m runtime.harness scripts/pint_compute.py \
    convert "5 meters" --to feet

uv run python -m runtime.harness scripts/pint_compute.py \
    convert "100 km/h" --to mph

uv run python -m runtime.harness scripts/pint_compute.py \
    convert "1 atmosphere" --to pascal

calc

Perform unit-aware arithmetic. Operators must be space-separated.

uv run python -m runtime.harness scripts/pint_compute.py \
    calc "5 m * 3 s"

uv run python -m runtime.harness scripts/pint_compute.py \
    calc "10 m / 2 s"

uv run python -m runtime.harness scripts/pint_compute.py \
    calc "5 meters + 300 cm"

check

Check if two units have compatible dimensions.

uv run python -m runtime.harness scripts/pint_compute.py \
    check newton --against "kg * m / s^2"

uv run python -m runtime.harness scripts/pint_compute.py \
    check joule --against "kg * m^2 / s^2"

simplify

Simplify compound units to base or compact form.

uv run python -m runtime.harness scripts/pint_compute.py \
    simplify "1 kg*m/s^2"

uv run python -m runtime.harness scripts/pint_compute.py \
    simplify "1000 m"

Common Unit Domains

Domain
Examples

Length
meter, foot, inch, mile, km, yard

Time
second, minute, hour, day, year

Mass
kg, gram, pound, ounce, ton

Velocity
m/s, km/h, mph, knot

Energy
joule, calorie, eV, kWh, BTU

Force
newton, pound_force, dyne

Temperature
kelvin, celsius, fahrenheit

Pressure
pascal, bar, atmosphere, psi

Power
watt, horsepower

Output Format

All commands return JSON with relevant fields:

{
  "result": "16.4042 foot",
  "magnitude": 16.4042,
  "units": "foot",
  "dimensionality": "[length]",
  "latex": "16.4042\\,\\mathrm{ft}"
}

Error Handling

Dimensionality errors are caught and reported:

# This will error - incompatible dimensions
uv run python -m runtime.harness scripts/pint_compute.py \
    convert "5 meters" --to kg
# Error: Cannot convert '[length]' to '[mass]'

Related Skills

/math-mode - Full math orchestration (SymPy + Z3)

/sympy-compute - Symbolic computation