FrenchCurve.Chart (FrenchCurve v0.1.3)

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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)

Summary

Functions

area(values, opts \\ [])

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

line(values, opts \\ [])

Plots values as a polyline.

Functions

area(values, opts \\ [])

@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(values, opts \\ [])

@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 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.