Another fix for descending domains.

d3 · Sep 2, 2019 · cdd3452 · cdd3452
1 parent 903f39d
commit cdd3452
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Showing 2 changed files with 22 additions and 4 deletions.
diff --git a/src/diverging.js b/src/diverging.js
@@ -42,7 +42,7 @@ function transformer() {
   };
 
   return function(t) {
-    transform = t, t0 = t(x0), t1 = t(x1), t2 = t(x2), k10 = t0 === t1 ? 0 : 0.5 / (t1 - t0), k21 = t1 === t2 ? 0 : 0.5 / (t2 - t1);
+    transform = t, t0 = t(x0), t1 = t(x1), t2 = t(x2), k10 = t0 === t1 ? 0 : 0.5 / (t1 - t0), k21 = t1 === t2 ? 0 : 0.5 / (t2 - t1), s = t1 < t0 ? -1 : 1;
     return scale;
   };
 }

diff --git a/test/diverging-test.js b/test/diverging-test.js
@@ -60,9 +60,27 @@ tape("diverging.domain() handles a degenerate domain", function(test) {
 tape("diverging.domain() handles a descending domain", function(test) {
   var s = scale.scaleDiverging().domain([4, 2, 1]);
   test.deepEqual(s.domain(), [4, 2, 1]);
-  test.equal(s( 1.2), 0.9);
-  test.equal(s( 2.0), 0.5);
-  test.equal(s( 3.0), 0.25);
+  test.equal(s(1.2), 0.9);
+  test.equal(s(2.0), 0.5);
+  test.equal(s(3.0), 0.25);
+  test.end();
+});
+
+tape("divergingLog.domain() handles a descending domain", function(test) {
+  var s = scale.scaleDivergingLog().domain([3, 2, 1]);
+  test.deepEqual(s.domain(), [3, 2, 1]);
+  test.equal(s(1.2), 1 - 0.1315172029168969);
+  test.equal(s(2.0), 1 - 0.5000000000000000);
+  test.equal(s(2.8), 1 - 0.9149213210862197);
+  test.end();
+});
+
+tape("divergingLog.domain() handles a descending negative domain", function(test) {
+  var s = scale.scaleDivergingLog().domain([-1, -2, -3]);
+  test.deepEqual(s.domain(), [-1, -2, -3]);
+  test.equal(s(-1.2), 0.1315172029168969);
+  test.equal(s(-2.0), 0.5000000000000000);
+  test.equal(s(-2.8), 0.9149213210862197);
   test.end();
 });