handle splom Axes.expand calls w/ undefined xa/ya

Author: etpinard

src/plots/cartesian/autorange.js

@@ -232,6 +232,7 @@ function doAutoRange(ax) {
  *          and make it a tight bound if possible
  */
 function expand(ax, data, options) {
+
     if(!ax._min) ax._min = [];
     if(!ax._max) ax._max = [];
     if(!options) options = {};

src/traces/scatter/calc.js

@@ -96,8 +96,9 @@ function calcAxisExpansion(gd, trace, xa, ya, x, y, ppad) {
         yOptions.padded = false;
     }
 
-    Axes.expand(xa, x, xOptions);
-    Axes.expand(ya, y, yOptions);
+    // N.B. asymmetric splom traces call this with undefined xa or ya
+    if(xa._id) Axes.expand(xa, x, xOptions);
+    if(ya._id) Axes.expand(ya, y, yOptions);
 }
 
 function calcMarkerSize(trace, serieslen) {