do not coerce scale* attrs when violin 'width' is set

- do not fill in fullLayout._violinScaleGroupStats
  for traces with set 'width'
- use maxKDE key instead of maxWidth to avoid confusing

Author: etpinard

src/traces/violin/calc.js

@@ -25,18 +25,10 @@ module.exports = function calc(gd, trace) {
         trace[trace.orientation === 'h' ? 'xaxis' : 'yaxis']
     );
 
-    var violinScaleGroupStats = fullLayout._violinScaleGroupStats;
-    var scaleGroup = trace.scalegroup;
-    var groupStats = violinScaleGroupStats[scaleGroup];
-    if(!groupStats) {
-        groupStats = violinScaleGroupStats[scaleGroup] = {
-            maxWidth: 0,
-            maxCount: 0
-        };
-    }
-
     var spanMin = Infinity;
     var spanMax = -Infinity;
+    var maxKDE = 0;
+    var maxCount = 0;
 
     for(var i = 0; i < cd.length; i++) {
         var cdi = cd[i];
@@ -61,19 +53,36 @@ module.exports = function calc(gd, trace) {
 
         for(var k = 0, t = span[0]; t < (span[1] + step / 2); k++, t += step) {
             var v = kde(t);
-            groupStats.maxWidth = Math.max(groupStats.maxWidth, v);
             cdi.density[k] = {v: v, t: t};
+            maxKDE = Math.max(maxKDE, v);
         }
 
-        groupStats.maxCount = Math.max(groupStats.maxCount, vals.length);
-
+        maxCount = Math.max(maxCount, vals.length);
         spanMin = Math.min(spanMin, span[0]);
         spanMax = Math.max(spanMax, span[1]);
     }
 
     var extremes = Axes.findExtremes(valAxis, [spanMin, spanMax], {padded: true});
     trace._extremes[valAxis._id] = extremes;
 
+    if(trace.width) {
+        cd[0].t.maxKDE = maxKDE;
+    } else {
+        var violinScaleGroupStats = fullLayout._violinScaleGroupStats;
+        var scaleGroup = trace.scalegroup;
+        var groupStats = violinScaleGroupStats[scaleGroup];
+
+        if(groupStats) {
+            groupStats.maxKDE = Math.max(groupStats.maxKDE, maxKDE);
+            groupStats.maxCount = Math.max(groupStats.maxCount, maxCount);
+        } else {
+            violinScaleGroupStats[scaleGroup] = {
+                maxKDE: maxKDE,
+                maxCount: maxCount
+            };
+        }
+    }
+
     cd[0].t.labels.kde = Lib._(gd, 'kde:');
 
     return cd;

src/traces/violin/defaults.js

@@ -27,13 +27,11 @@ module.exports = function supplyDefaults(traceIn, traceOut, defaultColor, layout
 
     coerce('bandwidth');
     coerce('side');
+
     var width = coerce('width');
     if(!width) {
         coerce('scalegroup', traceOut.name);
         coerce('scalemode');
-    } else {
-        traceOut.scalegroup = '';
-        traceOut.scalemode = 'width';
     }
 
     var span = coerce('span');

src/traces/violin/plot.js

@@ -78,7 +78,6 @@ module.exports = function plot(gd, plotinfo, cdViolins, violinLayer) {
         var hasBothSides = trace.side === 'both';
         var hasPositiveSide = hasBothSides || trace.side === 'positive';
         var hasNegativeSide = hasBothSides || trace.side === 'negative';
-        var groupStats = fullLayout._violinScaleGroupStats[trace.scalegroup];
 
         var violins = plotGroup.selectAll('path.violin').data(Lib.identity);
 
@@ -94,15 +93,15 @@ module.exports = function plot(gd, plotinfo, cdViolins, violinLayer) {
             var len = density.length;
             var posCenter = d.pos + bPos;
             var posCenterPx = posAxis.c2p(posCenter);
-            var scale;
 
-            switch(trace.scalemode) {
-                case 'width':
-                    scale = groupStats.maxWidth / bdPos;
-                    break;
-                case 'count':
-                    scale = (groupStats.maxWidth / bdPos) * (groupStats.maxCount / d.pts.length);
-                    break;
+            var scale;
+            if(trace.width) {
+                scale = t.maxKDE / bdPos;
+            } else {
+                var groupStats = fullLayout._violinScaleGroupStats[trace.scalegroup];
+                scale = trace.scalemode === 'count' ?
+                    (groupStats.maxKDE / bdPos) * (groupStats.maxCount / d.pts.length) :
+                    groupStats.maxKDE / bdPos;
             }
 
             var pathPos, pathNeg, path;

test/jasmine/tests/violin_test.js

@@ -142,6 +142,23 @@ describe('Test violin defaults', function() {
         expect(traceOut.meanline.color).toBe('blue');
         expect(traceOut.meanline.width).toBe(10);
     });
+
+    it('should not coerce *scalegroup* and *scalemode* when *width* is set', function() {
+        _supply({
+            y: [1, 2, 1],
+            width: 1
+        });
+        expect(traceOut.scalemode).toBeUndefined();
+        expect(traceOut.scalegroup).toBeUndefined();
+
+        _supply({
+            y: [1, 2, 1],
+            // width=0 is ignored during calc
+            width: 0
+        });
+        expect(traceOut.scalemode).toBe('width');
+        expect(traceOut.scalegroup).toBe('');
+    });
 });
 
 describe('Test violin calc:', function() {
@@ -236,7 +253,7 @@ describe('Test violin calc:', function() {
             name: 'one',
             y: [0, 0, 0, 0, 10, 10, 10, 10]
         });
-        expect(fullLayout._violinScaleGroupStats.one.maxWidth).toBeCloseTo(0.055);
+        expect(fullLayout._violinScaleGroupStats.one.maxKDE).toBeCloseTo(0.055);
         expect(fullLayout._violinScaleGroupStats.one.maxCount).toBe(8);
     });