Plot stacked Area chart with two categories columns

[quillcraft]

Im new in Observable Plot and have a problem.
How to stack two categories in data correctly in Plot so that stacked area chart does not break?

Stacked two categories

[Fil]

The issue in this chart is that the dataset has two series (for females and males), so it’s not expressable as a simple stacked area chart. You need to:

• add M and F together for a total population analysis, or
• filter on M or F (`filter: d => d.sex === “female”`), or
• facet by sex (`fx: “sex”`)

The last option gives you this:

[quillcraft]

Yes, you’re right. I think it may be possible to add M and F series with Plot.stack and after that make stacked area chart with another Plot.stack with fill by category?

[Fil]

You could use `z` to make distinct areas for each {sex, category} combination like so:

Plot.plot({
  marks: [
    Plot.areaY(
      data,
      Plot.stackY(
        {
          order: "category",
          reverse: true
        },
        {
          x: "age",
          y: "population",
          fill: "category",
          z: (d) => `${d.sex} ${d.category}`
        }
      )
    )
  ]
})

[quillcraft]

Thanks!