Curiosity - 2D Array Data Structure

Hello @leeoniya ,

It seems to me there are at least 3 primary ways to structure data for a given chart/plot library. You choose to use a 2D array.

Q) Can you tell me how you weighed the pros and cons? What was the most important, what was secondary? How do you evaluate this 2D nested array data structure since the creation of uPlot?

I have hunch, that it's about flexibility to not be subjected to time on the x-axis.

Style 1: Nested Array (2D Array)

data, like uPlot's AlignedData

let data = [
  [1546300800, 1546387200],
  [35, 71],
  [90, 15],
];

And metadata is in another structure, to hold labels, color, and meaning.

Style 2: Time Sample Objects in Array

data is self describing with props like time, temp. Similar to recharts.

const data = [
  { value: 14, temp: 90, time: 1503617297689 },
  { value: 15, temp: 80, time: 1503616962277 },
  { value: 7, temp: null, time: 1503616882654 },
  { value: 7, temp: null, time: 1503616882654 },
  { value: 31, time: 1503616882654 },
  { value: 30, time: 1503616882654 },
  { value: 20, temp: 50, time: 1503613184594 },
  { value: 11, temp: 20, time: 1503611308914 },
];

And metadata is in another structure, to hold labels, color.

Style 3: Joined

data and metadata together. Similar to SciChart.

[
  {
    dataSeries: {
      dataSeriesName: "",
      dataSeries: [
        { i, value },
        { i, value },
      ],
    },
    stroke: "",
    thickness: "",
  },
  {
    dataSeries: {
      dataSeriesName: "",
      dataSeries: [
        { i, value },
        { i, value },
      ],
    },
    stroke: "",
    thickness: "",
  },
];

Thanks so much!

No source file or test is named. Start by reviewing uPlot's AlignedData representation and compare it with the three data shapes shown in the issue; done would be a documented explanation of the tradeoffs and the rationale for uPlot's 2D array structure.