how to configure the `domain` of color in a heatmap at top level

Hi,

I have constructed a heatmap chart with numerical data and now I would like to control the heatmap color domain at the top level. The Chart.configure_range() seems to be a possible way but so far I haven’t figured out how it can work. However, I do notice that in the vega-lite spec, I can easily change the domain to say, from 0 to 10000 like this:

...
"scales": [
...
   {
      "name": "color",
      "type": "sequential",
      "domain": [0,10000],
      "range": {"scheme": "redyellowblue"},
      "zero": false,
      "reverse": true
    }
],
...

My question is, is there an equivalent way to do the same thing with a constructed Chart instance? Thanks.

[jakevdp]

Yes, every Vega-Lite command maps directly to an Altair command. The snippet above appears to be part of a Vega spec rather than vega-lite spec, though, so there is no altair equivalent.

The way you can control scales within Altair/Vega-Lite is via the scale property of the encoding; for example:

alt.Chart(data).encode(
    color=alt.Color('color:Q', scale=alt.Scale(domain=[0, 10000]))
)

[xujiboy]

This is great reference. Thank you very much Jake.