Fix NaN in clamped log scale inversion.

tobie · Jan 1, 2012 · 149d174 · 149d174
1 parent 5bae5f4
commit 149d174
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Showing 4 changed files with 18 additions and 8 deletions.
diff --git a/d3.js b/d3.js
@@ -2578,11 +2578,11 @@ function d3_scale_log(linear, log) {
 var d3_scale_logFormat = d3.format(".0e");
 
 function d3_scale_logp(x) {
-  return Math.log(x) / Math.LN10;
+  return Math.log(x < 0 ? 0 : x) / Math.LN10;
 }
 
 function d3_scale_logn(x) {
-  return -Math.log(-x) / Math.LN10;
+  return -Math.log(x > 0 ? 0 : -x) / Math.LN10;
 }
 
 d3_scale_logp.pow = function(x) {

diff --git a/d3.min.js b/d3.min.js
diff --git a/src/scale/log.js b/src/scale/log.js
@@ -69,11 +69,11 @@ function d3_scale_log(linear, log) {
 var d3_scale_logFormat = d3.format(".0e");
 
 function d3_scale_logp(x) {
-  return Math.log(x) / Math.LN10;
+  return Math.log(x < 0 ? 0 : x) / Math.LN10;
 }
 
 function d3_scale_logn(x) {
-  return -Math.log(-x) / Math.LN10;
+  return -Math.log(x > 0 ? 0 : -x) / Math.LN10;
 }
 
 d3_scale_logp.pow = function(x) {

diff --git a/test/scale/log-test.js b/test/scale/log-test.js
@@ -106,13 +106,23 @@ suite.addBatch({
       },
       "can clamp to the domain": function(log) {
         var x = log().clamp(true);
-        assert.inDelta(x(.5), 0, 1e-6);
+        assert.inDelta(x(-1), 0, 1e-6);
         assert.inDelta(x(5), 0.69897, 1e-6);
         assert.inDelta(x(15), 1, 1e-6);
         var x = log().domain([10, 1]).clamp(true);
-        assert.inDelta(x(.5), 1, 1e-6);
+        assert.inDelta(x(-1), 1, 1e-6);
         assert.inDelta(x(5), 0.30103, 1e-6);
         assert.inDelta(x(15), 0, 1e-6);
+      },
+      "can clamp to the range": function(log) {
+        var x = log().clamp(true);
+        assert.inDelta(x.invert(-.1), 1, 1e-6);
+        assert.inDelta(x.invert(0.69897), 5, 1e-6);
+        assert.inDelta(x.invert(1.5), 10, 1e-6);
+        var x = log().domain([10, 1]).clamp(true);
+        assert.inDelta(x.invert(-.1), 10, 1e-6);
+        assert.inDelta(x.invert(0.30103), 5, 1e-6);
+        assert.inDelta(x.invert(1.5), 1, 1e-6);
       }
     },