AI-generated Key Takeaways
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Calculates the total length of the linear segments within a geometry, excluding any polygonal areas.
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For MultiPolygons, the total length is the sum of the lengths of all linear components across all polygons.
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The length can be calculated in meters or in the units of a specified projection.
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An optional
maxError
parameter controls the error tolerance during reprojection if a projection is used.
Usage | Returns |
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MultiPolygon.length(maxError, proj) | Float |
Argument | Type | Details |
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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 MultiPolygon object. var multiPolygon = ee.Geometry.MultiPolygon( [[[[-122.092, 37.424], [-122.086, 37.418], [-122.079, 37.425], [-122.085, 37.423]]], [[[-122.081, 37.417], [-122.086, 37.421], [-122.089, 37.416]]]]); // Apply the length method to the MultiPolygon object. var multiPolygonLength = multiPolygon.length(); // Print the result to the console. print('multiPolygon.length(...) =', multiPolygonLength); // Display relevant geometries on the map. Map.setCenter(-122.085, 37.422, 15); Map.addLayer(multiPolygon, {'color': 'black'}, 'Geometry [black]: multiPolygon');
import ee import geemap.core as geemap
Colab (Python)
# Define a MultiPolygon object. multipolygon = ee.Geometry.MultiPolygon([ [[ [-122.092, 37.424], [-122.086, 37.418], [-122.079, 37.425], [-122.085, 37.423], ]], [[[-122.081, 37.417], [-122.086, 37.421], [-122.089, 37.416]]], ]) # Apply the length method to the MultiPolygon object. multipolygon_length = multipolygon.length() # Print the result. display('multipolygon.length(...) =', multipolygon_length) # Display relevant geometries on the map. m = geemap.Map() m.set_center(-122.085, 37.422, 15) m.add_layer( multipolygon, {'color': 'black'}, 'Geometry [black]: multipolygon' ) m