Precursor visualisation for Altair color-binning "scales"

[edwardchalstrey1]

The altair colour binning parameter "scales" will be an interesting one to provide some kind of "pre-cursor" visualisation for, whereby either the plot gets shown with each different value "scale" parameter so users can easily see the difference, or some other way of making the difference clear, rather than the first method we tried of just showing all the options in a dropdown, which the user has to just click through to see the differences:

• Limit options available in the "scale" selection to ones that make sense for the particular kind of plot e.g. if WAYS recognises that the altair plot type is a choropleth etc

[edwardchalstrey1]

see vega/altair#1074 <- Is binning with log scale allowed?

We need to know this to understand whether all "Scale" options are relevant/work

[edwardchalstrey1]

see altair-viz/altair#1074 <- Is binning with log scale allowed?

We need to know this to understand whether all "Scale" options are relevant/work

We now know that indeed the scales to not work when binning is enabled and have accounted for this see #77

[edwardchalstrey1]

@rolyp I'm going to move this to the proposed column as I think I'm going to spend the remaining time wrapping up what we've already done

[rolyp]

@edwardchalstrey1 I think that makes sense.