The places one geo dataset drew a value at, in dataset order.
A region whose value is null is skipped. It is still on the map -- the
colour scale paints it with options.missing rather than a shade -- but
the grammar's y is a number, and emitting one would announce and sonify a
value the map declines to show. The same rule the bar family follows for a
gap.
Answers with the value and the parsed datum rather than the position alone,
so the payload half needs no second reading of the same metadata -- and so
the value arrives already narrowed, rather than as a cast asserting what
this function has just tested.
Exported because the highlight half has to walk these the same way: the
plugin outlines by index through the table computeTargetMaps builds, and
a table built by a different walk names a different mark from the one the
payload announces (#1024). Sharing this is what keeps the two paired.
Dataset order rather than a drawn order: a map has no category axis to
reverse, so the projection draws the regions where the geometry puts them
and dataset.data is the only order there is.
The places one geo dataset drew a value at, in dataset order.
A region whose value is
nullis skipped. It is still on the map -- the colour scale paints it withoptions.missingrather than a shade -- but the grammar'syis a number, and emitting one would announce and sonify a value the map declines to show. The same rule the bar family follows for a gap.Answers with the value and the parsed datum rather than the position alone, so the payload half needs no second reading of the same metadata -- and so the value arrives already narrowed, rather than as a cast asserting what this function has just tested.
Exported because the highlight half has to walk these the same way: the plugin outlines by index through the table
computeTargetMapsbuilds, and a table built by a different walk names a different mark from the one the payload announces (#1024). Sharing this is what keeps the two paired.Dataset order rather than a drawn order: a map has no category axis to reverse, so the projection draws the regions where the geometry puts them and
dataset.datais the only order there is.