code: function(iStartX, iTickSize) {
          this.xTicks = [];
          this.xTickSize = iTickSize;
          
          var tickMap = {};
  
          for (var i = this.initPageX; i >= this.minX; i = i - iTickSize) {
              if (!tickMap[i]) {
                  this.xTicks[this.xTicks.length] = i;
                  tickMap[i] = true;
              }
          }
  
          for (i = this.initPageX; i <= this.maxX; i = i + iTickSize) {
              if (!tickMap[i]) {
                  this.xTicks[this.xTicks.length] = i;
                  tickMap[i] = true;
              }
          }
  
          this.xTicks.sort(this.DDM.numericSort) ;
          this.logger.log("xTicks: " + this.xTicks.join());
      }
docs: Create the array of horizontal tick marks if an interval was specified
  in setXConstraint().
  @method setXTicks
  @private