simplify logic for axis breaks in zoomAxRanges

Author: archmoj

src/plots/cartesian/dragbox.js

@@ -987,13 +987,12 @@ function zoomAxRanges(axList, r0Fraction, r1Fraction, updates, linkedAxes) {
         if(axi.fixedrange) continue;
 
         if(axi.breaks) {
-            if(axi._id.charAt(0) === 'y') {
-                updates[axi._name + '.range[0]'] = axi.l2r(axi.p2l((1 - r0Fraction) * axi._length));
-                updates[axi._name + '.range[1]'] = axi.l2r(axi.p2l((1 - r1Fraction) * axi._length));
-            } else {
-                updates[axi._name + '.range[0]'] = axi.l2r(axi.p2l(r0Fraction * axi._length));
-                updates[axi._name + '.range[1]'] = axi.l2r(axi.p2l(r1Fraction * axi._length));
-            }
+            var isY = axi._id.charAt(0) === 'y';
+            var r0F = isY ? (1 - r0Fraction) : r0Fraction;
+            var r1F = isY ? (1 - r1Fraction) : r1Fraction;
+
+            updates[axi._name + '.range[0]'] = axi.l2r(axi.p2l(r0F * axi._length));
+            updates[axi._name + '.range[1]'] = axi.l2r(axi.p2l(r1F * axi._length));
         } else {
             var axRangeLinear0 = axi._rl[0];
             var axRangeLinearSpan = axi._rl[1] - axRangeLinear0;