2024-01-27-vega-lite.md

layout	post
title	a post with vega lite
date	2024-01-26 16:20:00 -0800
last_updated	2024-04-13 21:30:00 -0700
description	this is what included vega lite code could look like
tags	formatting charts
categories	sample-posts
chart	vega_lite true

This is an example post with some vega lite code.

```vega_lite
{
  "$schema": "https://vega.github.io/schema/vega-lite/v5.json",
  "description": "A dot plot showing each movie in the database, and the difference from the average movie rating. The display is sorted by year to visualize everything in sequential order. The graph is for all Movies before 2019.",
  "data": {
    "url": "https://raw.githubusercontent.com/vega/vega/main/docs/data/movies.json"
  },
  "transform": [
    {"filter": "datum['IMDB Rating'] != null"},
    {"filter": {"timeUnit": "year", "field": "Release Date", "range": [null, 2019]}},
    {
      "joinaggregate": [{
        "op": "mean",
        "field": "IMDB Rating",
        "as": "AverageRating"
      }]
    },
    {
      "calculate": "datum['IMDB Rating'] - datum.AverageRating",
      "as": "RatingDelta"
    }
  ],
  "mark": "point",
  "encoding": {
    "x": {
      "field": "Release Date",
      "type": "temporal"
    },
    "y": {
      "field": "RatingDelta",
      "type": "quantitative",
      "title": "Rating Delta"
    },
    "color": {
      "field": "RatingDelta",
      "type": "quantitative",
      "scale": {"domainMid": 0},
      "title": "Rating Delta"
    }
  }
}
```

Which generates:

{
  "$schema": "https://vega.github.io/schema/vega-lite/v5.json",
  "description": "A dot plot showing each movie in the database, and the difference from the average movie rating. The display is sorted by year to visualize everything in sequential order. The graph is for all Movies before 2019.",
  "data": {
    "url": "https://raw.githubusercontent.com/vega/vega/main/docs/data/movies.json"
  },
  "transform": [
    {"filter": "datum['IMDB Rating'] != null"},
    {"filter": {"timeUnit": "year", "field": "Release Date", "range": [null, 2019]}},
    {
      "joinaggregate": [{
        "op": "mean",
        "field": "IMDB Rating",
        "as": "AverageRating"
      }]
    },
    {
      "calculate": "datum['IMDB Rating'] - datum.AverageRating",
      "as": "RatingDelta"
    }
  ],
  "mark": "point",
  "encoding": {
    "x": {
      "field": "Release Date",
      "type": "temporal"
    },
    "y": {
      "field": "RatingDelta",
      "type": "quantitative",
      "title": "Rating Delta"
    },
    "color": {
      "field": "RatingDelta",
      "type": "quantitative",
      "scale": {"domainMid": 0},
      "title": "Rating Delta"
    }
  }
}

This plot supports both light and dark themes.