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ee.Geometry.MultiLineString.convexHull
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Returns the convex hull of the given geometry. The convex hull of a single point is the point itself, the convex hull of collinear points is a line, and the convex hull of everything else is a polygon. Note that a degenerate polygon with all vertices on the same line will result in a line segment.
| Usage | Returns | MultiLineString.convexHull(maxError, proj) | Geometry |
| Argument | Type | Details | this: geometry | Geometry | Calculates the convex hull of this geometry. |
maxError | ErrorMargin, default: null | The maximum amount of error tolerated when performing any necessary reprojection. |
proj | Projection, default: null | The projection in which to perform the operation. If not specified, the operation will be performed in a spherical coordinate system, and linear distances will be in meters on the sphere. |
Examples
Code Editor (JavaScript)
// Define a MultiLineString object.
var multiLineString = ee.Geometry.MultiLineString(
[[[-122.088, 37.418], [-122.086, 37.422], [-122.082, 37.418]],
[[-122.087, 37.416], [-122.083, 37.416], [-122.082, 37.419]]]);
// Apply the convexHull method to the MultiLineString object.
var multiLineStringConvexHull = multiLineString.convexHull({'maxError': 1});
// Print the result to the console.
print('multiLineString.convexHull(...) =', multiLineStringConvexHull);
// Display relevant geometries on the map.
Map.setCenter(-122.085, 37.422, 15);
Map.addLayer(multiLineString,
{'color': 'black'},
'Geometry [black]: multiLineString');
Map.addLayer(multiLineStringConvexHull,
{'color': 'red'},
'Result [red]: multiLineString.convexHull');
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 MultiLineString object.
multilinestring = ee.Geometry.MultiLineString([
[[-122.088, 37.418], [-122.086, 37.422], [-122.082, 37.418]],
[[-122.087, 37.416], [-122.083, 37.416], [-122.082, 37.419]],
])
# Apply the convexHull method to the MultiLineString object.
multilinestring_convex_hull = multilinestring.convexHull(maxError=1)
# Print the result.
display('multilinestring.convexHull(...) =', multilinestring_convex_hull)
# Display relevant geometries on the map.
m = geemap.Map()
m.set_center(-122.085, 37.422, 15)
m.add_layer(
multilinestring, {'color': 'black'}, 'Geometry [black]: multilinestring'
)
m.add_layer(
multilinestring_convex_hull,
{'color': 'red'},
'Result [red]: multilinestring.convexHull',
)
m
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Last updated 2024-07-13 UTC.
[null,null,["Last updated 2024-07-13 UTC."],[[["\u003cp\u003e\u003ccode\u003econvexHull()\u003c/code\u003e returns the smallest convex Geometry that contains all the points in the input Geometry.\u003c/p\u003e\n"],["\u003cp\u003eThe returned Geometry type can be a point, a line, or a polygon depending on the input Geometry.\u003c/p\u003e\n"],["\u003cp\u003eThis method accepts optional \u003ccode\u003emaxError\u003c/code\u003e and \u003ccode\u003eproj\u003c/code\u003e parameters for reprojection purposes.\u003c/p\u003e\n"],["\u003cp\u003eDegenerate polygons, where all vertices lie on the same line, will result in a line segment output.\u003c/p\u003e\n"]]],["The `convexHull` method calculates the convex hull of a given geometry. For a single point, it returns the point; for collinear points, it returns a line. Otherwise, it returns a polygon, which may be a line segment if degenerate. The method accepts `maxError` and `proj` arguments to control reprojection and coordinate systems, respectively. It is demonstrated using a `MultiLineString` object in both JavaScript and Python, showing how to create it and visualizing the original geometry and its convex hull.\n"],null,["# ee.Geometry.MultiLineString.convexHull\n\nReturns the convex hull of the given geometry. The convex hull of a single point is the point itself, the convex hull of collinear points is a line, and the convex hull of everything else is a polygon. Note that a degenerate polygon with all vertices on the same line will result in a line segment.\n\n\u003cbr /\u003e\n\n| Usage | Returns |\n|-------------------------------------------------------|----------|\n| MultiLineString.convexHull`(`*maxError* `, `*proj*`)` | Geometry |\n\n| Argument | Type | Details |\n|------------------|----------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|\n| this: `geometry` | Geometry | Calculates the convex hull of this geometry. |\n| `maxError` | ErrorMargin, default: null | The maximum amount of error tolerated when performing any necessary reprojection. |\n| `proj` | Projection, default: null | The projection in which to perform the operation. If not specified, the operation will be performed in a spherical coordinate system, and linear distances will be in meters on the sphere. |\n\nExamples\n--------\n\n### Code Editor (JavaScript)\n\n```javascript\n// Define a MultiLineString object.\nvar multiLineString = ee.Geometry.MultiLineString(\n [[[-122.088, 37.418], [-122.086, 37.422], [-122.082, 37.418]],\n [[-122.087, 37.416], [-122.083, 37.416], [-122.082, 37.419]]]);\n\n// Apply the convexHull method to the MultiLineString object.\nvar multiLineStringConvexHull = multiLineString.convexHull({'maxError': 1});\n\n// Print the result to the console.\nprint('multiLineString.convexHull(...) =', multiLineStringConvexHull);\n\n// Display relevant geometries on the map.\nMap.setCenter(-122.085, 37.422, 15);\nMap.addLayer(multiLineString,\n {'color': 'black'},\n 'Geometry [black]: multiLineString');\nMap.addLayer(multiLineStringConvexHull,\n {'color': 'red'},\n 'Result [red]: multiLineString.convexHull');\n```\nPython setup\n\nSee the [Python Environment](/earth-engine/guides/python_install) page for information on the Python API and using\n`geemap` for interactive development. \n\n```python\nimport ee\nimport geemap.core as geemap\n```\n\n### Colab (Python)\n\n```python\n# Define a MultiLineString object.\nmultilinestring = ee.Geometry.MultiLineString([\n [[-122.088, 37.418], [-122.086, 37.422], [-122.082, 37.418]],\n [[-122.087, 37.416], [-122.083, 37.416], [-122.082, 37.419]],\n])\n\n# Apply the convexHull method to the MultiLineString object.\nmultilinestring_convex_hull = multilinestring.convexHull(maxError=1)\n\n# Print the result.\ndisplay('multilinestring.convexHull(...) =', multilinestring_convex_hull)\n\n# Display relevant geometries on the map.\nm = geemap.Map()\nm.set_center(-122.085, 37.422, 15)\nm.add_layer(\n multilinestring, {'color': 'black'}, 'Geometry [black]: multilinestring'\n)\nm.add_layer(\n multilinestring_convex_hull,\n {'color': 'red'},\n 'Result [red]: multilinestring.convexHull',\n)\nm\n```"]]