# `Localize.Number.Formatter.Ratio`
[🔗](https://github.com/elixir-localize/localize/blob/v0.38.0/lib/localize/number/formatter/ratio.ex#L1)

Formats numbers as rational fractions using CLDR rational format patterns.

Rational fractions contain a numerator and denominator (e.g., ½) and
may also have an integer part (e.g., 5½). The formatter supports
three rendering preferences:

* `:default` — fraction slash with visible space between integer
  and fraction (e.g., "5 1⁄2").

* `:super_sub` — superscript numerator and subscript denominator
  with zero-width joiner (e.g., "5⁠¹⁄₂").

* `:precomposed` — Unicode vulgar fraction characters when
  available (e.g., "5½").

# `to_ratio_string`

```elixir
@spec to_ratio_string(number() | Decimal.t(), Keyword.t()) ::
  {:ok, String.t()} | {:error, Exception.t()}
```

Formats a number as a rational fraction string.

### Arguments

* `number` is an integer, float, or Decimal.

* `options` is a keyword list of options.

### Options

* `:locale` is a locale identifier. The default is
  `Localize.get_locale()`.

* `:prefer` is a list of rendering preferences. Valid values
  are `:default`, `:super_sub`, and `:precomposed`. The default
  is `[:default]`.

* `:max_denominator` is the largest permitted denominator.
  The default is `10`.

* `:max_iterations` is the maximum number of continued fraction
  iterations. The default is `20`.

* `:epsilon` is the tolerance for float comparisons. The default
  is `1.0e-10`.

### Returns

* `{:ok, formatted_string}` on success.

* `{:error, exception}` if the number cannot be converted to
  a ratio or locale data is unavailable.

---

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