Follow alex advice

Author: LoganWlv

src/plots/cartesian/set_convert.js

@@ -180,7 +180,7 @@ module.exports = function setConvert(ax, fullLayout) {
     function getCategoryPosition(v) {
         // d2l/d2c variant that that won't add categories but will also
         // allow numbers to be mapped to the linearized axis positions
-        var index = getRangePosition(v);
+        var index = getCategoryIndex(v);
         if(index !== undefined) return index;
         if(isNumeric(v)) return +v;
     }
@@ -320,12 +320,12 @@ module.exports = function setConvert(ax, fullLayout) {
         ax.d2r = ax.d2l_noadd = getCategoryPosition;
 
         ax.r2c = function(v) {
-            var index = getCategoryPosition(v);
+            var index = getRangePosition(v);
             return index !== undefined ? index : ax.fraction2r(0.5);
         };
 
         ax.l2r = ax.c2r = ensureNumber;
-        ax.r2l = getCategoryPosition;
+        ax.r2l = getRangePosition;
 
         ax.d2p = function(v) { return ax.l2p(ax.r2c(v)); };
         ax.p2d = function(px) { return getCategoryName(p2l(px)); };