Vega not rendering Word Cloud

[crazyphil (Phil)]

I'm trying to build a word cloud using Vega and running into an issue where I can't seem to get at the data that I know is loaded. I'm not sure what value I use for the "field" references, I may also need a transform in my data section. Any suggestions would be greatly welcomed.

EDIT: I played around with my data using a bar chart and got data to display - so I've adjusted my field names accordingly, and updated my config. However, I still get nothing to display on the word cloud.

I've attached a screenshot of the javascript console showing data is in VEGA_DEBUG.

Vega Word Cloud example: https://vega.github.io/vega/examples/word-cloud/

Config:

{
  "$schema": "https://vega.github.io/schema/vega/v4.json",
  "title": "Twitter Word Cloud",
  data: [
  {
    "name": "table",
    url: 
      {
        "%context%": true,
        "%timefield%": "@timestamp",
        "index": "twitter-cleaned-reporters-*",
        "body": {
          "size":0,
          "aggs": {
             "wordcloud": {
               "terms": {
                 "field": "text",
                 "size": 50,
                 "exclude": ["https","the","a","t.co","of","in","and","is","on","for","that","this","it","with","i","at","was","to","be","he","his","as","but","from","are","about","has","you","have","by","an","who","what","me","says","had","our","or","no","so","if","not","new","one","we","out","just","my","said","will","up","would","news","more","they","amp","after","than","there","their","been","when","say","people","him","some","her","how","like","think","did","get","do","most","were","could","can","going","last","all","first","back","it's","here","via","also","year","your","which","because","into","next","wide","over","years","asked","she","only","rep","them","robert","story","know","it’s","other","day","make","way","being","read","great","want","should","very","those","any","still","may"]
              }
            }
          }
        }
    },
      "transform": [
        {
          "type": "formula", "as": "angle",
          "expr": "[-45, 0, 45][~~(random() * 3)]"
        },
        {
          "type": "formula", "as": "weight",
          "expr": "if(datum.text=='VEGA', 600, 300)"
        }
      ]

  }
  ],
    "scales": [
    {
      "name": "color",
      "type": "ordinal",
      "domain": {"data": "table", "field": "doc_count"},
      "range": ["#d5a928", "#652c90", "#939597"]
    }
  ],

  "marks": [
    {
      "type": "text",
      "from": {"data": "table"},
      "encode": {
        "enter": {
          "text": {"field": "key"},
          "align": {"value": "center"},
          "baseline": {"value": "alphabetic"},
          "fill": {"scale": "color", "field": "key"}
        },
        "update": {
          "fillOpacity": {"value": 1}
        },
        "hover": {
          "fillOpacity": {"value": 0.5}
        }
      },
      "transform": [
        {
          "type": "wordcloud",
          "size": [800, 400],
          "text": {"field": "key"},
          "rotate": {"field": "datum.angle"},
          "font": "Helvetica Neue, Arial",
          "fontSize": {"field": "doc_count"},
          "fontWeight": {"field": "datum.weight"},
          "fontSizeRange": [12, 56],
          "padding": 2
        }
      ]
    }
  ]
}

[jen-huang]

Hi, can you please follow the steps here so that we have some more information about your data? https://gist.github.com/nyurik/736c34970ba3c32f3fe3d45d66719b3e

[jen-huang]

Looking at this closer, I have a couple of suggestions:

• Add format: {property: "aggregations.wordcloud.buckets"}, similar to this example

• Change or remove the transform that includes if(datum.text=='VEGA', 600, 300). Your result only has key and doc_count, so the expression should be datum.key not datum.text.

• In these two expressions: "rotate": {"field": "datum.angle"} and "fontWeight": {"field": "datum.weight"}, field automatically prepends datum, so it's not necessary to add that. You can just change these values to "field": "angle" for example. Or you can use signal notation, but that only makes sense if you were creating an expression with those fields, such as "rotate": {"signal": "datum.angle * 2"}.

[crazyphil (Phil)]

Ok - after reviewing your suggestions here's what I figured out:

1. Adding a "title" field can completely destroy the word cloud's ability to function (may have something to do with autosize/fit)
2. In the transform section I needed "datum.angle", "datum.weight" AND "datum.doc_count" to make it work
3. The best number of buckets seems to be between 50 and 75, otherwise the word cloud becomes stacked on top of itself
4. The format property is required to make the data show (I think I finally understand what format does - for others having similar issues - format "points" Vega at the table of data it needs to work - so from a json perspective the "aggs" field does not tell Vega enough to print the data)

Thanks for your help Jen!