Why am I seeing an empty density plot, despite no errors in the editor log?

Question

As a learning exercise I decided to try plotting a density plot of continuously-compounded daily returns of the Nasdaq 100 index for calendar year 2020. I am unable to get vega-lite to produce any visualization, and yet there are no errors in the online editor. I'm just inexplicably given an empty plot.

Because of the embedded data, the plot spec is some 2500 lines long, so I've saved it as a gist: https://gist.github.com/nathanvy/2c080ee0b7e93b11e544c5275d31f2b1

What am I missing?

Answer 1

Change logreturn to value:

 "$schema": "https://vega.github.io/schema/vega-lite/v5.json",
  "width": 300,
  "height": 300,
  "title": "Nasdaq 100 (NDX) Log Returns, 2020",
  "mark": "area",
  "transform": [{"density": "logreturn"}],
  "encoding": {
    "x": {
      "field": "value",
      "title": "Logarithmic Daily Return",
      "type": "quantitative"
    },
    "y": {
      "field": "density",
      "title": "Probability of Return",
      "type": "quantitative"
    }
  }