React-Native-Maps: How to animate to coordinate?

I've had some issues where this.refs is undefined, unless I bind a reference to this in the constructor to the function I am using this.refs in. In your case, try this:

constructor(props) {
    super(props);
    this._getCoords = this._getCoords.bind(this);
    this.state = {
        position: null
    };
}

componentDidMount() {
    this._getCoords();
}

_getCoords = () => {
    navigator.geolocation.getCurrentPosition(
        (position) => {
            var initialPosition = JSON.stringify(position.coords);
            this.setState({position: initialPosition});
            let tempCoords = {
                latitude: Number(position.coords.latitude),
                longitude: Number(position.coords.longitude)
            }
            this._map.animateToCoordinate(tempCoords, 1);
          }, function (error) { alert(error) },
     );
};

render() {
    return (
         <MapView.Animated
             ref={component => this._map = component}
          />
    );

}

Although using string refs is still possible, I believe that is legacy now, so I've also updated the MapView ref to the newer way. See: Ref Example

Unfortunately now animateToCoordinate is deprecated and if you want to do the same, you should use animateCamera or animateToRegion instead.

render() {
  return ( 
    <MapView style = {styles.maps}
      ref = {(mapView) => { _mapView = mapView; }}
      initialRegion = {{
        latitude: 6.8523,
        longitude: 79.8895,
        latitudeDelta: 0.0922,
        longitudeDelta: 0.0421,
      }}
    />
    <TouchableOpacity 
       onPress = {() => _mapView.animateToRegion({
        latitude: LATITUDE,
        longitude: LONGITUDE
      }, 1000)}>
      <Text>Tap</Text>
    </TouchableOpacity>
  )

}

In my case I used animateToCoordinate() like follows and it works for me:

  var _mapView: MapView;

  render() {
      return ( 
        <MapView style = {styles.maps}
          ref = {(mapView) => { _mapView = mapView; }}
          initialRegion = {{
            latitude: 6.8523,
            longitude: 79.8895,
            latitudeDelta: 0.0922,
            longitudeDelta: 0.0421,
          }}
        />
        <TouchableOpacity 
           onPress = {() => _mapView.animateToCoordinate({
            latitude: LATITUDE,
            longitude: LONGITUDE
          }, 1000)}>
          <Text>Tap</Text>
        </TouchableOpacity>
      )
  }