I have a variable coming out of a device as follows:

 "variable": "gps_info", 
  "value": "true", 
  "location": {
    "lat":latitude, "lng": longitude    
  }

Occasionally the values of lat and lng are zeros. How can I add a formula to the map display to not show these zeros? I would typically do something like " =0 ? None: " but how I act on a pair of numbers?