Question

Can you dynamically build axis labels using values from other columns in a Deneb Vega-Lite chart?

In Vega-Lite via Deneb, I want to create custom axis labels that combine values from multiple columns (e.g., category + region). I need a way to construct dynamic labels on the fly to make the axes more informative and context-aware.

Answer 1

Yes, you can dynamically build axis labels in Deneb (Vega-Lite) by creating a calculated field that combines values from multiple columns.

 How to do it

Use a calculated field in your encoding:

"encoding": {
  "x": {
    "field": "CombinedLabel",
    "type": "ordinal",
    "axis": {"title": "Category + Region"}
  }
}

Then define CombinedLabel in a transform:

"transform": [
  {
    "calculate": "datum.Category + ' - ' + datum.Region",
    "as": "CombinedLabel"
  }
]

• Use calculate transform to combine columns.

• Bind the new field to the axis for dynamic labeling.

• This makes your axis labels more descriptive and context-aware.