Dots, lines and polygons are
just (yet another) Mark Types.
To have zipcodes on a (filled) map
one needs the Marks for them --
at least one for each zipcode.
To draw the Marks one has to have
a pair of (non-empty) Lat / Lon columns
in the datasource (or as a row-level calc).
Last but not least, one would like to draw
those Marks on both panes of a Dual-Axis map,
hence the modified Path Order calculation --
with an added "path to nowhere" for the Null Route --
covering all "orphan" zipcodes on the way.
Please find the attached.
Hope it helps.
LightRail2_YF.twbx 392.4 KB