ee.Geometry.Polygon.length

AI-generated Key Takeaways

• The length method returns the length of the linear parts of a geometry, ignoring polygonal parts.

• For multi-geometries, the length is the sum of the lengths of their components.

• The method accepts optional maxError and proj arguments to control reprojection and the units of the result.

Returns the length of the linear parts of the geometry. Polygonal parts are ignored. The length of multi geometries is the sum of the lengths of their components.

Usage	Returns
Polygon.length(maxError, proj)	Float

Argument	Type	Details
this: geometry	Geometry	The input geometry.
maxError	ErrorMargin, default: null	The maximum amount of error tolerated when performing any necessary reprojection.
proj	Projection, default: null	If specified, the result will be in the units of the coordinate system of this projection. Otherwise it will be in meters.

Examples

Code Editor (JavaScript)

// Define a Polygon object.
var polygon = ee.Geometry.Polygon(
    [[[-122.092, 37.424],
      [-122.086, 37.418],
      [-122.079, 37.425],
      [-122.085, 37.423]]]);

// Apply the length method to the Polygon object.
var polygonLength = polygon.length();

// Print the result to the console.
print('polygon.length(...) =', polygonLength);

// Display relevant geometries on the map.
Map.setCenter(-122.085, 37.422, 15);
Map.addLayer(polygon,
             {'color': 'black'},
             'Geometry [black]: polygon');

Python setup

See the Python Environment page for information on the Python API and using geemap for interactive development.

import ee
import geemap.core as geemap

Colab (Python)

# Define a Polygon object.
polygon = ee.Geometry.Polygon([[
    [-122.092, 37.424],
    [-122.086, 37.418],
    [-122.079, 37.425],
    [-122.085, 37.423],
]])

# Apply the length method to the Polygon object.
polygon_length = polygon.length()

# Print the result.
display('polygon.length(...) =', polygon_length)

# Display relevant geometries on the map.
m = geemap.Map()
m.set_center(-122.085, 37.422, 15)
m.add_layer(polygon, {'color': 'black'}, 'Geometry [black]: polygon')
m