# `FrenchCurve.Chart`
[🔗](https://github.com/jaman/french_curve/blob/v0.1.4/lib/french_curve/chart.ex#L1)

Plots a series of numbers as a line or filled-area chart on a `FrenchCurve.Raster`.

Both functions take a flat list of values and lay them out evenly across the raster's
width, scaling them to its height. There are no axes, labels or gridlines: the result is
the plotted series and nothing else, ready to hand to `FrenchCurve.render/3`.

Values map to pixels so that the first sits at `x = 0` and the last at `x = width - 1`,
and the data minimum sits at the bottom row with the maximum at the top. A series whose
values are all equal is drawn along the bottom.

    [3, 1, 4, 1, 5, 9, 2, 6]
    |> FrenchCurve.Chart.area(width: 120, height: 40, smooth: true)
    |> FrenchCurve.to_terminal(:kitty)

# `area`

```elixir
@spec area(
  [number()],
  keyword()
) :: FrenchCurve.Raster.t()
```

Plots `values` as a polyline with the space beneath it filled down to the bottom row.

An empty list returns a blank raster of the requested size.

Takes every option of `line/2`, plus:

  * `:fill_opacity` — factor applied to the red, green and blue channels of `:color` to
    get the fill colour, default `0.4`. The alpha channel is copied unchanged, so the
    fill is a darkened `:color` at the same opacity rather than a translucent one.

# `line`

```elixir
@spec line(
  [number()],
  keyword()
) :: FrenchCurve.Raster.t()
```

Plots `values` as a polyline.

An empty list returns a blank raster of the requested size.

## Options

  * `:width` — raster width in pixels, default `80`
  * `:height` — raster height in pixels, default `24`
  * `:color` — the line's `t:FrenchCurve.Raster.color/0`, default `{255, 255, 255, 255}`
  * `:background` — raster background colour, default transparent
  * `:min` — value pinned to the bottom row, default the smallest of `values`
  * `:max` — value pinned to the top row, default the largest of `values`
  * `:smooth` — interpolate a Catmull-Rom spline through the points, default `false`

Values outside `:min`/`:max` are plotted off the raster and clipped away.

---

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