BarGraph

A vector-rendered bar chart with filled rectangles. Bars, axes, and labels are drawn as canvas overlays. The legend is rendered on the ASCII grid. Supports multiple series (grouped bars).

Constructor

new BarGraph(series: Series[], options?: BarGraphOptions)

Series

interface Series {
  label: string
  values: number[]
  color: string
}

Multiple series produce grouped bars (side-by-side within each x position).

BarGraphOptions

Property	Type	Default	Description
xLabels	string[]	Index numbers	X-axis labels
yMin	number	0	Minimum y value
yMax	number	Auto	Maximum y value
yTicks	number	5	Number of y-axis ticks
legend	boolean	true	Show ASCII legend
legendPosition	'top' | 'bottom'	'top'	Legend placement
glow	number	3	Bar glow radius (0 to disable)
valueLabels	boolean	false	Show value above each bar
gridLines	boolean	false	Show horizontal grid lines
barFill	number	0.8	Bar fill ratio within slot (0-1)

Properties

Property	Type	Description
overlays	ComponentOverlays	Rects/vectors/texts/colors produced during render

Methods

render()

render(width: number, height: number): CharGrid

Returns an ASCII grid (mostly blank, with legend text). Populates overlays with VectorRect entries for bars, plus vectors for axes and texts for labels.

setData()

setData(series: Series[]): void

Example

// single series
const chart = new BarGraph([
  { label: 'Sales', values: [120, 95, 140, 85], color: palette.BLUE },
], {
  xLabels: ['Q1', 'Q2', 'Q3', 'Q4'],
  valueLabels: true,
})

// multiple series (grouped)
const chart = new BarGraph([
  { label: '2024', values: [120, 95, 140], color: palette.BLUE },
  { label: '2025', values: [150, 110, 130], color: palette.CYAN },
], {
  xLabels: ['North', 'South', 'East'],
  gridLines: true,
})

// in a layout
const layout = new Box('Revenue', chart)
grid.overlay(g, layout.render(60, 20), 5, 3)
const overlays = grid.collectOverlays(layout, 5, 3)
return { grid: g, ...overlays }