Feature columns

There are special columns representing features. They are declared at dataframe creation time. They are used internaly to make calculations and provide info in computed properties. Feature columns:

  • geometry

    declares a geometry. Data types: GeoPoint or GeoSerie

  • time

    the date column. Data type: DateTime. Note: this column is created from timestamps

  • speed

    the speed column: unit is meters per second. Data type: double

Only the geometry column is required. The others are optional. Example:

final data = <Map<String, dynamic>>[
   <String,dynamic>{
      "geometry": GeoPoint(latitude: 51.0, longitude: 0.0),
      "timestamp": 125855222,
      "speed": 0.0
   },
];
final df = GeoDataFrame.fromRecords(data,
     geometryCol: "geometry",
     speedCol: "speed",
     timestampCol: "timestamp");

featureCols

Get feature columns info:

final fcols = df.featureCols();
final timeCol = df.fcols.timeCol;

Shortcuts to get feature columns info:

final timeCol = df.timeCol;
final geomCol = df.geometryCol;
final speedCol = df.speedCol;
// internal type
print(speedCol.dtype);
// dart type
print(speedCol.type);