closes #2085

src/marks/geo.js

@@ -23,6 +23,8 @@ export class Geo extends Mark {
       data,
       {
         geometry: {value: options.geometry, scale: "projection"},
+        x: {value: options.x, scale: "x", optional: true},
+        y: {value: options.y, scale: "y", optional: true},
         r: {value: vr, scale: "r", filter: positive, optional: true}
       },
       withDefaultSort(options),

src/transforms/centroid.js

@@ -16,14 +16,16 @@ export function centroid({geometry = identity, ...options} = {}) {
       facets,
       channels: {
         x: {value: X, scale: projection == null ? "x" : null, source: null},
-        y: {value: Y, scale: projection == null ? "y" : null, source: null}
+        y: {value: Y, scale: projection == null ? "y" : null, source: null},
+        geometry: {value: G}
       }
     };
   });
 }
 
-export function geoCentroid({geometry = identity, ...options} = {}) {
+export function geoCentroid(options = {}) {
   let C;
+  const {geometry = identity} = options;
   return {
     ...options,
     x: {transform: (data) => Float64Array.from((C = valueof(valueof(data, geometry), GeoCentroid)), ([x]) => x)},

test/data/README.md

@@ -115,6 +115,13 @@ CBO
 https://www.cbo.gov/topics/budget/accuracy-projections
 https://observablehq.com/@tophtucker/examples-of-bitemporal-charts
 
+## london.json
+giCentre, City University of London
+https://github.com/gicentre/data
+
+## london-car-access.csv
+Jo Wood, TK
+
 ## metros.csv
 The New York Times
 https://www.nytimes.com/2019/12/02/upshot/wealth-poverty-divide-american-cities.html

test/data/london-car-access.csv

@@ -0,0 +1,34 @@
+borough,y2001,y2011,y2021
+City of London,0.380,0.306,0.228
+Barking and Dagenham,0.621,0.604,0.652
+Barnet,0.733,0.713,0.701
+Bexley,0.763,0.763,0.776
+Brent,0.627,0.570,0.559
+Bromley,0.770,0.765,0.771
+Camden,0.444,0.389,0.364
+Croydon,0.702,0.665,0.664
+Ealing,0.683,0.647,0.632
+Enfield,0.715,0.675,0.690
+Greenwich,0.592,0.580,0.569
+Hammersmith and Fulham,0.514,0.448,0.425
+Haringey,0.535,0.482,0.473
+Harrow,0.773,0.765,0.753
+Havering,0.767,0.770,0.785
+Hillingdon,0.783,0.773,0.777
+Hounslow,0.714,0.684,0.672
+Islington,0.424,0.353,0.331
+Kensington and Chelsea,0.496,0.440,0.417
+Kingston upon Thames,0.762,0.749,0.743
+Lambeth,0.491,0.422,0.420
+Lewisham,0.572,0.519,0.523
+Merton,0.699,0.674,0.670
+Newham,0.511,0.479,0.483
+Redbridge,0.738,0.721,0.725
+Richmond upon Thames,0.763,0.753,0.746
+Southwark,0.481,0.416,0.397
+Sutton,0.767,0.766,0.772
+Tower Hamlets,0.432,0.370,0.336
+Waltham Forest,0.610,0.581,0.579
+Wandsworth,0.593,0.547,0.521
+Westminster,0.436,0.371,0.338
+Hackney,0.440,0.354,0.351