dotbin

joshpoll · Dec 5, 2020 · 8832a80 · 8832a80
1 parent 73840b0
commit 8832a80
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Showing 5 changed files with 49 additions and 9 deletions.
diff --git a/src/defined.js b/src/defined.js
@@ -18,3 +18,7 @@ export function filter(index, ...channels) {
   }
   return index;
 }
+
+export function positive(x) {
+  return x > 0 ? x : NaN;
+}
diff --git a/src/marks/dot.js b/src/marks/dot.js
@@ -1,6 +1,6 @@
 import {ascending} from "d3-array";
 import {create} from "d3-selection";
-import {filter, nonempty} from "../defined.js";
+import {filter, nonempty, positive} from "../defined.js";
 import {Mark, indexOf, identity, first, second, maybeColor, maybeNumber} from "../mark.js";
 import {Style, applyDirectStyles, applyIndirectStyles, applyBandTransform} from "../style.js";
 
@@ -48,7 +48,7 @@ export class Dot extends Mark {
     {x, y, r, color},
     {x: X, y: Y, z: Z, r: R, title: L, fill: F, stroke: S}
   ) {
-    const index = filter(I, X, Y, R, F, S);
+    const index = filter(I, X, Y, F, S).filter(i => positive(R[i]));
     if (Z) index.sort((i, j) => ascending(Z[i], Z[j]));
     return create("svg:g")
         .call(applyIndirectStyles, this)

diff --git a/src/scales/quantitative.js b/src/scales/quantitative.js
@@ -50,6 +50,7 @@ import {
 } from "d3-scale-chromatic";
 import {scaleDiverging, scaleLinear, scaleLog, scalePow, scaleSymlog} from "d3-scale";
 import {registry, radius, color} from "./index.js";
+import {positive} from "../defined.js";
 
 const constant = x => () => x;
 const flip = i => t => i(1 - t);
@@ -213,9 +214,11 @@ function inferDomain(channels) {
   ];
 }
 
+// We don’t want the upper bound of the radial domain to be zero, as this would
+// be degenerate, so we ignore nonpositive values.
 function inferRadialDomain(channels) {
   return [
     0,
-    quantile(channels, 0.5, ({value}) => value === undefined ? value : quantile(value, 0.25))
+    quantile(channels, 0.5, ({value}) => value === undefined ? NaN : quantile(value, 0.25, positive))
   ];
 }
diff --git a/src/transforms/bin.js b/src/transforms/bin.js
@@ -26,10 +26,8 @@ export function bin1(options = {}) {
 }
 
 export function bin2({x = {}, y = {}, domain, thresholds} = {}) {
-  if (isvalue(x)) x = {value: x};
-  if (isvalue(y)) y = {value: y};
-  const binX = bin1({domain, thresholds, value: first, ...x});
-  const binY = bin1({domain, thresholds, value: second, ...y});
+  const binX = bin1({domain, thresholds, value: first, ...maybeValue(x)});
+  const binY = bin1({domain, thresholds, value: second, ...maybeValue(y)});
   return data => {
     return cross(binX(data), binY(data).map(binset), (x, y) => {
       return {
@@ -43,8 +41,11 @@ export function bin2({x = {}, y = {}, domain, thresholds} = {}) {
   };
 }
 
-function isvalue(x) {
-  return typeof x === "string" || typeof x === "function";
+// The value may be defined as a string or function, rather than an object with
+// a value property. TODO Allow value to be specified as array, too? This would
+// require promoting the array to an accessor for compatibility with d3.bin.
+function maybeValue(x) {
+  return typeof x === "string" || typeof x === "function" ? {value: x} : x;
 }
 
 function binset(bin) {

diff --git a/test/diamonds-carat-price-dots.html b/test/diamonds-carat-price-dots.html
@@ -0,0 +1,32 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<body>
+<script src="https://cdn.jsdelivr.net/npm/d3@6"></script>
+<script src="../dist/@observablehq/plot.umd.js"></script>
+<script>
+
+d3.csv("data/diamonds.csv", d3.autoType).then(data => {
+  document.body.appendChild(Plot.plot({
+    height: 640,
+    grid: true,
+    x: {
+      label: "Carats →"
+    },
+    y: {
+      label: "↑ Price ($)"
+    },
+    r: {
+      domain: [0, 100]
+    },
+    marks: [
+      Plot.dot(data, {
+        transform: Plot.bin2({x: "carat", y: "price", thresholds: 100}),
+        x: d => (d.x0 + d.x1) / 2,
+        y: d => (d.y0 + d.y1) / 2,
+        r: "length"
+      })
+    ]
+  }));
+});
+
+</script>