GeoJSON vs Shapefile

formats/geojson-vs-shapefile — GeoJsonVsShapefile.cs

Writes the same polygons as a GeoJSON file and as a Shapefile (.shp + .shx) and prints the sizes. The answer depends on the coordinates, so the sample uses two generated data sets:

• a grid of 10,000 squares whose coordinates have at most two decimals;
• 2,000 circle-like polygons whose coordinates use the full double precision.

// GeoJSON: geometry -> IGeoJsonGeometry, then serialize
File.WriteAllText(geoJsonPath, JsonHelper.Serialize(polygons.Select(p => p.AsGeoJson()).ToList()));

// Shapefile: geometry -> Esri shape, then save (.dbf omitted — no attributes here)
var esriShapes = polygons.Select(p => p.AsEsriShape()).OfType<EsriShapeBase>().ToList();
Shapefile.Save(shapefilePath, esriShapes, createDbf: false, overwrite: true);

Typical output:

data set	GeoJSON	Shapefile	bytes per vertex (GeoJSON / Shapefile)
grid, short coordinates	1.24 MB	1.44 MB	31 / 36
circles, full precision	2.01 MB	0.93 MB	42 / 19

A Shapefile spends a fixed 16 bytes per vertex (two doubles) plus small record headers; GeoJSON spends one character per digit. Short coordinates favour text, real-world coordinates favour the binary format — and both lose to a compressed or tiled format for large data.

Output goes to %TEMP%\maptor-samples\geojson-vs-shapefile.

How to run

dotnet run --project samples/IRI.Maptor.Samples.Core -- formats/geojson-vs-shapefile

See also: GeoJSON · IRI.Maptor.Core.ShapefileFormat.

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