Instead of using a dispatch for handling 'highlightPoint' and 'clearHighlights', I am making

those functions a direct method of nv.models.scatter.  So you just say scatter.highlightPoint,
instead of scatter.dispatch.highlightPoint.

src/models/cumulativeLineChart.js

@@ -505,7 +505,7 @@ nv.models.cumulativeLineChart = function() {
 */
 
        interactiveLayer.dispatch.on('elementMousemove', function(e) {
-          lines.dispatch.clearHighlights();
+          lines.clearHighlights();
           var singlePoint, pointIndex, pointXLocation, allData = [];
           data
           .filter(function(series, i) { 
@@ -514,7 +514,7 @@ nv.models.cumulativeLineChart = function() {
           })
           .forEach(function(series,i) {
               pointIndex = nv.interactiveBisect(series.values, e.pointXValue, chart.x());
-              lines.dispatch.highlightPoint(i, pointIndex, true);
+              lines.highlightPoint(i, pointIndex, true);
               var point = series.values[pointIndex];
               if (typeof point === 'undefined') return;
               if (typeof singlePoint === 'undefined') singlePoint = point;
@@ -547,7 +547,7 @@ nv.models.cumulativeLineChart = function() {
 
       interactiveLayer.dispatch.on("elementMouseout",function(e) {
           dispatch.tooltipHide();
-          lines.dispatch.clearHighlights();
+          lines.clearHighlights();
       });
 
       dispatch.on('tooltipShow', function(e) {

src/models/line.js

@@ -209,7 +209,8 @@ nv.models.line = function() {
   chart.dispatch = scatter.dispatch;
   chart.scatter = scatter;
 
-  d3.rebind(chart, scatter, 'id', 'interactive', 'size', 'xScale', 'yScale', 'zScale', 'xDomain', 'yDomain', 'sizeDomain', 'forceX', 'forceY', 'forceSize', 'clipVoronoi', 'useVoronoi', 'clipRadius', 'padData');
+  d3.rebind(chart, scatter, 'id', 'interactive', 'size', 'xScale', 'yScale', 'zScale', 'xDomain', 'yDomain', 
+    'sizeDomain', 'forceX', 'forceY', 'forceSize', 'clipVoronoi', 'useVoronoi', 'clipRadius', 'padData','highlightPoint','clearHighlights');
 
   chart.margin = function(_) {
     if (!arguments.length) return margin;

src/models/lineChart.js

@@ -255,7 +255,7 @@ nv.models.lineChart = function() {
       
 
       interactiveLayer.dispatch.on('elementMousemove', function(e) {
-          lines.dispatch.clearHighlights();
+          lines.clearHighlights();
           var singlePoint, pointIndex, pointXLocation, allData = [];
           data
           .filter(function(series, i) { 
@@ -264,7 +264,7 @@ nv.models.lineChart = function() {
           })
           .forEach(function(series,i) {
               pointIndex = nv.interactiveBisect(series.values, e.pointXValue, chart.x());
-              lines.dispatch.highlightPoint(i, pointIndex, true);
+              lines.highlightPoint(i, pointIndex, true);
               var point = series.values[pointIndex];
               if (typeof point === 'undefined') return;
               if (typeof singlePoint === 'undefined') singlePoint = point;
@@ -297,7 +297,7 @@ nv.models.lineChart = function() {
 
       interactiveLayer.dispatch.on("elementMouseout",function(e) {
           dispatch.tooltipHide();
-          lines.dispatch.clearHighlights();
+          lines.clearHighlights();
       });
 
       dispatch.on('tooltipShow', function(e) {

src/models/scatter.js

@@ -34,7 +34,7 @@ nv.models.scatter = function() {
     , sizeDomain   = null // Override point size domain
     , sizeRange    = null
     , singlePoint  = false
-    , dispatch     = d3.dispatch('elementClick', 'elementMouseover', 'elementMouseout', 'highlightPoint', 'clearHighlights')
+    , dispatch     = d3.dispatch('elementClick', 'elementMouseover', 'elementMouseout')
     , useVoronoi   = true
     ;
 
@@ -432,20 +432,23 @@ nv.models.scatter = function() {
   //============================================================
   // Event Handling/Dispatching (out of chart's scope)
   //------------------------------------------------------------
-  dispatch.on('clearHighlights', function() {
+  chart.clearHighlights = function() {
+      //Remove the 'hover' class from all highlighted points.
       d3.selectAll(".nv-chart-" + id + " .nv-point.hover").classed("hover",false);
-  });
+  };
 
-  dispatch.on('highlightPoint', function(seriesIndex, pointIndex, isHoverOver) {
+  chart.highlightPoint = function(seriesIndex,pointIndex,isHoverOver) {
       d3.select(".nv-chart-" + id + " .nv-series-" + seriesIndex + " .nv-point-" + pointIndex)
-          .classed("hover",isHoverOver);     
-  });
+          .classed("hover",isHoverOver); 
+  };
+
+
   dispatch.on('elementMouseover.point', function(d) {
-     if (interactive) dispatch.highlightPoint(d.seriesIndex,d.pointIndex,true);
+     if (interactive) chart.highlightPoint(d.seriesIndex,d.pointIndex,true);
   });
 
   dispatch.on('elementMouseout.point', function(d) {
-     if (interactive) dispatch.highlightPoint(d.seriesIndex,d.pointIndex,false);
+     if (interactive) chart.highlightPoint(d.seriesIndex,d.pointIndex,false);
   });
 
   //============================================================

src/models/stackedArea.js

@@ -250,7 +250,8 @@ nv.models.stackedArea = function() {
   chart.dispatch = dispatch;
   chart.scatter = scatter;
 
-  d3.rebind(chart, scatter, 'interactive', 'size', 'xScale', 'yScale', 'zScale', 'xDomain', 'yDomain', 'sizeDomain', 'forceX', 'forceY', 'forceSize', 'clipVoronoi', 'useVoronoi','clipRadius');
+  d3.rebind(chart, scatter, 'interactive', 'size', 'xScale', 'yScale', 'zScale', 'xDomain', 'yDomain', 
+    'sizeDomain', 'forceX', 'forceY', 'forceSize', 'clipVoronoi', 'useVoronoi','clipRadius','highlightPoint','clearHighlights');
 
   chart.x = function(_) {
     if (!arguments.length) return getX;

src/models/stackedAreaChart.js

@@ -341,7 +341,7 @@ nv.models.stackedAreaChart = function() {
 
 
       interactiveLayer.dispatch.on('elementMousemove', function(e) {
-          stacked.scatter.dispatch.clearHighlights();
+          stacked.clearHighlights();
           var singlePoint, pointIndex, pointXLocation, allData = [];
           data
           .filter(function(series, i) { 
@@ -350,7 +350,7 @@ nv.models.stackedAreaChart = function() {
           })
           .forEach(function(series,i) {
               pointIndex = nv.interactiveBisect(series.values, e.pointXValue, chart.x());
-              stacked.scatter.dispatch.highlightPoint(i, pointIndex, true);
+              stacked.highlightPoint(i, pointIndex, true);
               var point = series.values[pointIndex];
               if (typeof point === 'undefined') return;
               if (typeof singlePoint === 'undefined') singlePoint = point;
@@ -383,7 +383,7 @@ nv.models.stackedAreaChart = function() {
 
       interactiveLayer.dispatch.on("elementMouseout",function(e) {
           dispatch.tooltipHide();
-          stacked.scatter.dispatch.clearHighlights();
+          stacked.clearHighlights();
       });