align autobinning of histogram traces on matching axes

Author: etpinard

src/traces/histogram/cross_trace_defaults.js

@@ -50,15 +50,16 @@ module.exports = function crossTraceDefaults(fullData, fullLayout) {
         binDirection = traceOut.orientation === 'v' ? 'x' : 'y';
         // in overlay mode make a separate group for each trace
         // otherwise collect all traces of the same subplot & orientation
-        group = isOverlay ? traceOut.uid : (traceOut.xaxis + traceOut.yaxis + binDirection);
-        traceOut._groupName = group;
-
+        group = traceOut._groupName = isOverlay ? traceOut.uid : (
+            getAxisGroup(fullLayout, traceOut.xaxis) +
+            getAxisGroup(fullLayout, traceOut.yaxis) +
+            binDirection
+        );
         binOpts = allBinOpts[group];
 
         if(binOpts) {
             binOpts.traces.push(traceOut);
-        }
-        else {
+        } else {
             binOpts = allBinOpts[group] = {
                 traces: [traceOut],
                 direction: binDirection
@@ -110,3 +111,13 @@ module.exports = function crossTraceDefaults(fullData, fullLayout) {
         }
     }
 };
+
+function getAxisGroup(fullLayout, axId) {
+    var matchGroups = fullLayout._axisMatchGroups;
+
+    for(var i = 0; i < matchGroups.length; i++) {
+        var group = matchGroups[i];
+        if(group[axId]) return 'g' + i;
+    }
+    return axId;
+}

test/image/baselines/hists-on-matching-axes.png

@@ -0,0 +1,84 @@
+{
+  "data": [
+    {
+      "type": "histogram",
+      "name": "sample A - <b>matched</b>",
+      "x": [1, 2, 3, 1, 1, 2, 3, 3],
+      "hoverlabel": {
+        "namelength": -1
+      }
+    },
+    {
+      "type": "histogram",
+      "name": "sample B - <b>matched</b>",
+      "x": [2.1, 2.1, 3.4, 1.3, 2.2, 2.1, 3.2, 4.1, 3.1],
+      "hoverlabel": {
+        "namelength": -1
+      },
+      "xaxis": "x2",
+      "yaxis": "y2"
+    },
+    {
+      "type": "histogram",
+      "name": "sample A - <b>not</b> on matching axes",
+      "x": [1, 2, 3, 1, 1, 2, 3, 3],
+      "hoverlabel": {
+        "namelength": -1
+      },
+      "xaxis": "x3",
+      "yaxis": "y3"
+    },
+    {
+      "type": "histogram",
+      "name": "sample B - <b>not</b> on matching axes",
+      "x": [2.1, 2.1, 3.4, 1.3, 2.2, 2.1, 3.2, 4.1, 3.1],
+      "hoverlabel": {
+        "namelength": -1
+      },
+      "xaxis": "x4",
+      "yaxis": "y4"
+    }
+  ],
+  "layout": {
+    "margin": {"t": 20, "b": 20},
+    "showlegend": false,
+    "xaxis": {
+      "domain": [0, 0.4]
+    },
+    "yaxis": {
+      "domain": [0.45, 1],
+      "title": {
+        "text": "Matched Axes"
+      }
+    },
+    "xaxis2": {
+      "domain": [0.45, 1],
+      "anchor": "y2",
+      "matches": "x"
+    },
+    "yaxis2": {
+      "domain": [0.45, 1],
+      "anchor": "x2",
+      "matches": "y"
+    },
+    "xaxis3": {
+      "domain": [0, 0.4],
+      "anchor": "y3"
+    },
+    "yaxis3": {
+      "domain": [0, 0.4],
+      "anchor": "x3",
+      "title": {
+        "text": "<b>NOT</b> Matched Axes"
+      }
+    },
+    "xaxis4": {
+      "domain": [0.45, 1],
+      "anchor": "y4"
+    },
+    "yaxis4": {
+      "domain": [0, 0.4],
+      "anchor": "x4"
+    }
+  }
+}