add 'len' argument to zip3

- to not have to .slice input array twice

Author: etpinard

src/plots/gl3d/zip3.js

@@ -9,7 +9,9 @@
 'use strict';
 
 module.exports = function zip3(x, y, z, len) {
-    var result = new Array(x.length);
+    len = len || x.length;
+
+    var result = new Array(len);
     for(var i = 0; i < len; i++) {
         result[i] = [x[i], y[i], z[i]];
     }

src/traces/cone/calc.js

@@ -14,7 +14,10 @@ module.exports = function calc(gd, trace) {
     var u = trace.u;
     var v = trace.v;
     var w = trace.w;
-    var len = Math.min(u.length, v.length, w.length);
+    var len = Math.min(
+        trace.x.length, trace.y.length, trace.z.length,
+        u.length, v.length, w.length
+    );
     var normMax = -Infinity;
     var normMin = Infinity;
 
@@ -28,6 +31,7 @@ module.exports = function calc(gd, trace) {
         normMin = Math.min(normMin, norm);
     }
 
+    trace._len = len;
     trace._normMax = normMax;
 
     colorscaleCalc(trace, [normMin, normMax], '', 'c');

src/traces/cone/convert.js

@@ -69,13 +69,15 @@ function convert(scene, trace) {
     coneOpts.vectors = zip3(
         toDataCoords(trace.u, 'xaxis'),
         toDataCoords(trace.v, 'yaxis'),
-        toDataCoords(trace.w, 'zaxis')
+        toDataCoords(trace.w, 'zaxis'),
+        trace._len
     );
 
     coneOpts.positions = zip3(
         toDataCoords(trace.x, 'xaxis'),
         toDataCoords(trace.y, 'yaxis'),
-        toDataCoords(trace.z, 'zaxis')
+        toDataCoords(trace.z, 'zaxis'),
+        trace._len
     );
 
     coneOpts.colormap = parseColorScale(trace.colorscale);

src/traces/streamtube/convert.js

@@ -86,11 +86,12 @@ function convert(scene, trace) {
         return Lib.simpleMap(arr, function(v) { return ax.d2l(v) * scale; });
     }
 
-    var u = toDataCoords(trace.u.slice(0, len), 'xaxis');
-    var v = toDataCoords(trace.v.slice(0, len), 'yaxis');
-    var w = toDataCoords(trace.w.slice(0, len), 'zaxis');
-
-    tubeOpts.vectors = zip3(u, v, w);
+    tubeOpts.vectors = zip3(
+        toDataCoords(trace.u, 'xaxis'),
+        toDataCoords(trace.v, 'yaxis'),
+        toDataCoords(trace.w, 'zaxis'),
+        len
+    );
 
     var valsx = distinctVals(trace.x.slice(0, len));
     var valsy = distinctVals(trace.y.slice(0, len));