the flow / origin-destination map

How much moved from where to where. Line thickness is the amount.

What it leaves outThe arc is a diagram, not the route anything actually travelled.

3 · geospatial · geo · rung 3 · what’s related

named, not shipped yet · ArcLayer -- no shape yet

Two worked examples

How much moved, and from where to where?

Before you lookWrite down which two places you expect the thickest arc between.

civicdots_la_311_points.csv · 1,500 rows · 4 columns · showing 400 of 1,500 rows on this page; the file has all of them

1,500 service requests, each with a real latitude and longitude

What to look atThese are the places requests came FROM. A flow needs a from AND a to, and this file has only one place per row — so nothing here moved. That absence is the finding.

What draws thisFour coordinate columns: an origin and a destination. No committed civic file carries both, and the pool refuses to invent the origin.

This example draws itself with a small script. With scripting off you can still read every word on this page, and the file itself is at data/dots_la_311_points.csv.

earth and spacetable_quakes_full.csv · 2,508 rows · 6 columns · showing 400 of 2,508 rows on this page; the file has all of them

earthquakes with a place name and coordinates

What to look atYou could join each quake to the town it is named after — but the file records where it happened, not where it went. Nothing moved.

What draws thisFour coordinate columns: an origin and a destination. Quakes have one place each, so this shape has no honest example here yet.

This example draws itself with a small script. With scripting off you can still read every word on this page, and the file itself is at data/table_quakes_full.csv.

the pool

Now build one yourself.

The pool opens with this file and this shape already drawn, so your first move is to change something rather than to start from nothing. Bring your own CSV if you have one. Nothing is uploaded anywhere — the chart is drawn in your browser, your work saves there, and it downloads as a picture or as a project file you can open again.

Open the pool → the flow / origin-destination map · dots_la_311_points.csv