Responsive Ordinal Scale (Ordinal Fit Mode)

[kanitw]

Currently config.cell.width, config.cell.height are ignored for x and y if they ordinal scales respectively.
Basically, the cell width and height of an ordinal scale is determined by the band size * cardinality.

• Let's add config.unit.fitOrdinalScale as boolean to make the ordinal scale rely on the config.unit.width/height value instead of bandWidth. See below
• Need to deal make the scale work with all mark type.
• corner case when the cardinality of the ordinal field is too high
• Of course, add tests.

[kanitw]

config.unit.fitOrdinalScale sounds confusing.

One possible way to make a readable syntax is the allow scale.bandWidth to be "fit" besides number.

@domoritz thoughts?

[domoritz]

scale.bandWidth with fit sounds much better.

[kanitw]

Earlier, we planned to allow scale.bandWidth to be "fit" to support ordinal scale fit.

Here I'm extending my thinking to #1421 (support width and height at the top-level).

1. If top-level width is provided, always use it (fit ordinal scale to width no matter scale.bandWidth is explicitly specified or not.)
2. else (If top-level width is not provided):

• For non-ordinal scale always use config.cell.width.
• For ordinal scale:
• If scale.bandSize is not "fit" (default = not fit), use bandSize * cardinality. -- Note that this is the default because it doesn't break with high cardinality.
• If scale.bandSize is "fit", use config.cell.width and fit the scale.

(Same logic for height)

@domoritz @jheer what do you think?

[kanitw]

(Just clarified the comment above after conversation with @arvind, who agrees with the proposal.)

[kanitw]

Done in #1214, pending docs revisions and should be ready for merging.

[devgru]

Looks like in vega-lite 2.0.1 this feature is removed?

[domoritz]

Looks like in vega-lite 2.0.1 this feature is removed?

It's been improved. Docs are at https://vega.github.io/vega-lite/docs/size.html.

[kanitw]

It is now called rangeStep, which is a bit more precise name. Basically, bandwidth supposes to be a fraction of range step. See https://vega.github.io/vega-lite/docs/scale.html#band for illustration.