Custom Visual dataViewMappings Setting Up

Unfortunatly no because the data in those axis columns is text not numbers.

If I change the capabilties.json file back to it's original form:

{
  "dataRoles": [
    {
      "displayName": "Values",
      "kind": "GroupingOrMeasure",
      "name": "Values"
    }
  ],
  "dataViewMappings": [
    {
      "scriptResult": {
        "dataInput": {
          "table": {
            "rows": {
              "select": [
                { "for": { "in": "Values" } }
              ],
              "dataReductionAlgorithm": {
                "top": {}
              }
            }
          }
        },
        "script": {
          "scriptProviderDefault": "R",
          "scriptOutputType": "html",
          "source": {
            "objectName": "rcv_script",
            "propertyName": "source"
          },
          "provider": {
            "objectName": "rcv_script",
            "propertyName": "provider"
          }
        }
      }
    }
  ],
  "objects": {
    "rcv_script": {
      "properties": {
        "provider": {
          "type": {
            "text": true
          }
        },
        "source": {
          "type": {
            "scripting": {
              "source": true
            }
          }
        }
      }
    }
  },
  "suppressDefaultTitle": true
}

I can then access in my r script Values$[columnName], but the columnNames need to be hard coded. I'm basically trying to genericize this visual so I can use it with other data. 

Is there a way of seeing table definition? I tried to view it through dataViews[0] but that didn't seem to be available in R. Also is there a way to debug the R script with the data being sent it?