vega-lite

What is vega-lite?

Vega-Lite is a high-level grammar of interactive graphics. It provides a concise JSON syntax for rapidly generating visualizations to support analysis. Vega-Lite specifications can be compiled to Vega specifications.

What are vega-lite's main functionalities?

Basic Chart

This code sample demonstrates how to create a simple bar chart using Vega-Lite. The data is embedded directly in the specification, and the chart maps the 'a' field to the x-axis and the 'b' field to the y-axis.

{
  "$schema": "https://vega.github.io/schema/vega-lite/v5.json",
  "description": "A simple bar chart with embedded data.",
  "data": {
    "values": [
      {"a": "A", "b": 28}, {"a": "B", "b": 55}, {"a": "C", "b": 43},
      {"a": "D", "b": 91}, {"a": "E", "b": 81}, {"a": "F", "b": 53},
      {"a": "G", "b": 19}, {"a": "H", "b": 87}, {"a": "I", "b": 52}
    ]
  },
  "mark": "bar",
  "encoding": {
    "x": {"field": "a", "type": "nominal", "axis": {"labelAngle": 0}},
    "y": {"field": "b", "type": "quantitative"}
  }
}

Interactive Chart

This code sample demonstrates how to create an interactive scatterplot using Vega-Lite. The chart allows users to select a region (brush) to highlight points based on the 'Cylinders' field.

{
  "$schema": "https://vega.github.io/schema/vega-lite/v5.json",
  "description": "A scatterplot with interactive selection.",
  "data": {"url": "data/cars.json"},
  "mark": "point",
  "encoding": {
    "x": {"field": "Horsepower", "type": "quantitative"},
    "y": {"field": "Miles_per_Gallon", "type": "quantitative"},
    "color": {
      "condition": {
        "selection": "brush",
        "field": "Cylinders",
        "type": "ordinal"
      },
      "value": "grey"
    }
  },
  "selection": {
    "brush": {"type": "interval"}
  }
}

Layered Chart

This code sample demonstrates how to create a layered chart using Vega-Lite. The chart combines a line mark and a point mark to visualize stock prices over time.

{
  "$schema": "https://vega.github.io/schema/vega-lite/v5.json",
  "description": "A layered chart with a line and point marks.",
  "data": {"url": "data/stocks.csv"},
  "layer": [
    {
      "mark": "line",
      "encoding": {
        "x": {"field": "date", "type": "temporal"},
        "y": {"field": "price", "type": "quantitative"},
        "color": {"field": "symbol", "type": "nominal"}
      }
    },
    {
      "mark": "point",
      "encoding": {
        "x": {"field": "date", "type": "temporal"},
        "y": {"field": "price", "type": "quantitative"},
        "color": {"field": "symbol", "type": "nominal"}
      }
    }
  ]
}

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README

Vega-Lite

Vega-Lite provides a higher-level grammar for visual analysis, akin to ggplot or Tableau, that generates complete Vega specifications.

You can find more details, documentation, examples, usage instructions, and tutorials on the Vega-Lite website.

Try using Vega-Lite in the online Vega Editor.

Contributions are also welcome. Please see CONTRIBUTING.md for contribution and development guidelines.

Team

The development of Vega-Lite is led by Kanit "Ham" Wongsuphasawat, Dominik Moritz, and Jeffrey Heer of the University Washington Interactive Data Lab, with significant help from Arvind Satyanarayan. Please see the contributors page for the full list of contributors.