Published-release documentation · release compatibility

Error Bar Recipe

Minimal flow

Runnable: install ggaction and provide the named data array as plain row objects.

import { chart } from "ggaction";

const program = chart()
  .createCanvas()
  .createData({ values })
  .createErrorBar({
    x: { field: "group", fieldType: "nominal" },
    y: { field: "value" }
  })
  .createGuides();

You must decide

• Independent nominal, ordinal, or temporal x field
• Quantitative y field

The library infers

• Current dataset and Cartesian coordinate
• Mean with a two-sided 95% Student-t confidence interval
• One immutable summary row per first-appearance group
• Vertical main rules, 8px caps, ordinal/temporal x, and quantitative y
• Axes, horizontal grid, and statistical axis title

When one compatible layer is already encoded, call createErrorBar() without options to reuse its fields, data, coordinate, and scales.

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Error-bar tutorial · Error-bar API