map
shaper
Settings
Simplify
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Layers
Add a file
Export menu
Layers
File format
?
Enter options from the command line interface. Examples: "bbox" "no-quantization" "precision=0.001"
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Export
Simplification menu
prevent shape removal
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Prevent small polygon features from disappearing at high simplification. Keeps the largest ring of multi-ring features.
use planar geometry
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Interpret x, y values as Cartesian coordinates on a plane, rather than longitude, latitude coordinates on a sphere.
Method
Douglas-Peucker
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Simplified lines remain within a set distance of original lines. Good for thinning dense points, but spikes tend to form at high simplification.
Visvalingam / effective area
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Lines are simplified by iteratively removing the point that forms the least-area triangle with two adjacent points.
Visvalingam / weighted area
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Points located at the vertex of more acute angles are preferentially removed, for a smoother appearance.
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Apply
Mapshaper is an editor for map data
Drop files here or
select
from a folder
Shapefile, GeoJSON, TopoJSON, DBF and CSV files are supported
Files can be loose or in a zip archive
Quick import
Drop files here to import with default settings
Options
detect line intersections
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Detect line intersections, including self-intersections, to help identify topological errors in a dataset.
snap vertices
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Fix topology errors by snapping together points with nearly identical coordinates. This option does not apply to TopoJSON files.
?
Enter options from the command line interface. Examples: "no-topology" "encoding=big5"
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Select
Import
0 line intersections
Repair
