Gauge chart

Use a gauge to show where a single value stands against a scale the reader already knows, such as a score out of 100 or a target.

Source

```chart
type: gauge
title: Customer satisfaction is fair, short of good
subtitle: Survey score out of 100
data:
  inline:
    - {measure: Satisfaction, score: 72}
encoding: {x: measure, y: score}
axes:
  y: {label: Score}
style:
  min: 0
  max: 100
  bands:
    - {to: 50, label: Poor}
    - {to: 75, label: Fair}
    - {to: 100, label: Good}
```

Fields that matter

• type: gauge with encoding.y for the value; encoding.x is an optional name shown under it
• A gauge holds one row per panel; use encoding.facet for one gauge per row
• style.min and style.max set the scale (they default to 0 and the end of the last band, or the next round number above the value); a value outside the scale is drawn at its edge and counted
• style.bands is a list of {to, label, color}, each band running from the end of the one before; label defaults to the range, and color picks a palette slot, otherwise bands take the style’s ramp from light to dark
• With bands the arc is split and a needle points at the value, and a key under the arc names every band; without them the arc fills up to the value
• RichView draws the bands as written and grades nothing; axes.y sets label, format and unit

Interactions

• Hover or focus the chart to read the value, its band and the scale.
• Open the Table view, Download PNG or CSV, or Expand the chart.