code: function(properties, data) {
              var axisProperties = this.parseUtils.getXAxisProperties(properties),
                  orientation = (this.axesAreInverted) ? 'vertical' : 'horizontal',
                  colorScheme = this.getAxisColorScheme();
  
              // add some extra info to the axisProperties as needed
              if(axisProperties.hasOwnProperty('axisTitle.text')){
                  axisProperties['axisTitle.text'] = Splunk.JSCharting.ParsingUtils.escapeHtml(axisProperties['axisTitle.text']);
              }
              axisProperties.chartType = properties.chart;
              axisProperties.axisLength = $(this.renderTo).width();
  
              this.xAxis = new Splunk.JSCharting.NumericAxis(axisProperties, data, orientation, colorScheme);
              this.hcConfig.xAxis = $.extend(true, this.xAxis.getConfig(), {
                  startOnTick: true,
                  endOnTick: true,
                  minPadding: 0,
                  maxPadding: 0
              });
          }
docs: override force the x axis to be numeric