ee.Geometry.Polygon.perimeter

  • Calculates the total length of all the sides of a polygon or the sum of perimeters for multi-part polygons.

  • Returns the perimeter value as a float, which can be in meters or the units of a specified projection.

  • Accepts optional parameters for error tolerance during reprojection (maxError) and output projection (proj).

  • Can be applied to Geometry objects using the perimeter() method in both JavaScript and Python.

 Returns the length of the perimeter of the polygonal parts of the geometry. The perimeter of multi geometries is the sum of the perimeters of their components.

UsageReturns
Polygon.perimeter(maxError, proj)Float
ArgumentTypeDetails
this: geometryGeometryThe input geometry.
maxErrorErrorMargin, default: nullThe maximum amount of error tolerated when performing any necessary reprojection.
projProjection, default: nullIf 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 perimeter method to the Polygon object.
var polygonPerimeter = polygon.perimeter({'maxError': 1});

// Print the result to the console.
print('polygon.perimeter(...) =', polygonPerimeter);

// 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 perimeter method to the Polygon object.
polygon_perimeter = polygon.perimeter(maxError=1)

# Print the result.
display('polygon.perimeter(...) =', polygon_perimeter)

# 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