title: NSMangedObject not letting access an objects data
body: <p>I am using CoreData and I have an NSManagedObject of type Thing.  When I set a breakpoint I can console "po aThing" and it shows the data stored.</p>
  
  <pre><code>{
      thingID = 5181c56063ab02c4d1000016;
      distance = "2.075121";
      lat = "37.815834";
      lng = "-122.406417";
  }
  </code></pre>
  
  <p>But, if I try to access the lat or lng (which are doubles in Core Data). I get "nan" returned.
   If I try "po aThing.lat" the console shows nan.</p>
  
  <p>If I try "po aThing.thingID" the console shows 5181c56063ab02c4d1000016.</p>
  
  <p>If I try to assign like newThing.lat = aThing.lat then newThing.lat becomes nan.</p>
  
  <p>I am guessing it has to do with the data be a double?</p>
  
  <p>UPDATE:</p>
  
  <p>Here is how my .h had properties</p>
  
  <pre><code>@property (nonatomic) double lat;
  @property (nonatomic) double lng;
  </code></pre>
  
  <p>Here is how I was using them </p>
  
  <pre><code>coordinate.latitude = thing.lat;
  coordinate.longitude = thing.lng;
  </code></pre>
  
  <p>Here is how I changed them </p>
  
  <pre><code>@property (nonatomic) double *lat;
  @property (nonatomic) double *lng;
  </code></pre>
  
  <p>And how I use them now and it seems to work</p>
  
  <pre><code>coordinate.latitude = *(thing.lat);
  coordinate.longitude = *(thing.lng);
  </code></pre>