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"}
      }
    }
  ]
}

Other packages similar to vega-lite

plotly.js

Plotly.js is a high-level, declarative charting library. It supports a wide range of chart types and is highly interactive. Compared to Vega-Lite, Plotly.js offers more built-in interactivity and a broader range of chart types, but it can be more complex to use.

chart.js

Chart.js is a simple yet flexible JavaScript charting library. It offers a variety of chart types and is easy to use for basic visualizations. Compared to Vega-Lite, Chart.js is more straightforward but less powerful for complex, interactive visualizations.

d3

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README

Vega-Lite 2 BETA

Announcement: The master branch now hosts ongoing Vega-Lite 2.0 pre-release development. We have migrated Vega-Lite to use the new Vega 3 Beta and D3 v4 and include basic composition and interaction features from our research publication. However, some composition and interaction features are still under development.

For a more stable version, please use Vega-Lite v1. We have created branch 1.x as our v1 maintenance branch.

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, Arvind Satyanarayan, and Jeffrey Heer of the University Washington Interactive Data Lab. Please see the contributors page for the full list of contributors.