# `AstroUtils.Math`
[🔗](https://github.com/jakedjohnson/astro_utils/blob/v0.1.0/lib/astro_utils/math.ex#L1)

Small numeric helpers shared across the library.

# `roundn`

```elixir
@spec roundn(float(), 0..15) :: float()
```

Round a float to `precision` decimal places.

A thin wrapper over `Float.round/2`, mainly useful for trimming the noise
digits that trigonometry leaves behind when comparing or displaying
results. Ties round away from zero, so `1.5` becomes `2.0` and `-1.5`
becomes `-2.0`.

`float` must be a float; an integer raises `FunctionClauseError`.
`precision` must be an integer in `0..15`; anything larger raises
`ArgumentError`.

## Examples

    iex> AstroUtils.Math.roundn(1.23456, 2)
    1.23

    iex> AstroUtils.Math.roundn(1.23456)
    1.2346

    iex> AstroUtils.Math.roundn(:math.cos(:math.pi() / 2), 12)
    0.0

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*Consult [api-reference.md](api-reference.md) for complete listing*