vega-lite: Setting only `width` when using `autosize: fit` should not use default height in compiled Vega

if we do this, wouldn’t it be impossible to specify something like

{ “width”: 200, “autosize”: “fit-x” }

without vega-lite adding in the default height as well? Or is that intentional?

Vega-Lite already always add default width/height if not specified (always a number for continuous and number or step for discrete) as in:

width = specifiedWidth || config.view.xxxWidth 

Basically, the width/height always have to come from somewhere anyway. So this issue is about how to apply the width/height (to just the axis or fit to axis + padding for label/title), not about how we get width/height.

width = specifiedWidth || config.view.xxxWidth

Of I understand @kanitw’s comment correctly, he assumes that we add fit-x and fit-y.

Yes, my proposed scheme works better with width and height.

should “autosize”: “fit” and “width”: 200 on QxQ compile to fit in Vega (and apply height config)?

Yes. Good point that it differs a bit from https://github.com/vega/vega-lite/issues/5133#issuecomment-513447536.

But we can simplify a lot of logic by saying that

width = specifiedWidth || config.view.xxxWidth // where XXX depends on whether x is discrete or continuous

Then the logic is simply “drop the ‘x’ part of fit when width (as defined above) is based on a step size”.

Note that we drop step when if x is continuous (as it’s invalid), so this logic should come after we drop step.

The same logic can be applied for “height” and “y”.

I think this actually simplifies the logic as compared to the comment above. Basically, we shouldn’t distinguish the width/height values whether it’s explicitly specified or derived from config.

Yes. In https://github.com/vega/vega-lite/issues/5133#issuecomment-513447536, you proposed to change VL, though, right? I am not yet convinced that we need to change the VL language.

Once that lands, you probably want to:

• Update model.fit to be {x: boolean, y: boolean} instead of boolean and update their references accordingly.
• Document the behavior in size.md

Thanks for volunteering to help. 😃

1. would require changing Vega. Maybe 1. is simpler to do?