sane-topojson

sane-topojson

Ready-to-use multi-layer topojson files.

This project encompasses the three step required to turn Natural Earth Data into topojson files.

These are:

• npm run wget: download to Natural Earth shapefiles and unzips them
• npm run shp2geo: clip and convert shapefiles into geojson files
• npm run geo2topo add properties and convert the geojson files into topojson files

Configuration

In ./config.json:

• resolutions: array of resolutions to output
• scopes: array of scopes to output

sane-topojson will output resolution.length times scopes.length topojson files.

• vectors: array of layers making up each topojson file

Output

A topojson with the objects field:

{
    coastlines: {
        type: '',
        geometries: []    
    },
    countries: {
        type: '',
        geometries: [
            {type: '', id: '', arcs: [], properties: {ct: [lon, lat]}},
            // ...
        ]
    },
    lakes: {
        type: '',
        geometries: []    
    },
    land: {
        type: '',
        geometries: []    
    },
    ocean: {
        type: '',
        geometries: []    
    }
    rivers: {
        type: '',
        geometries: []    
    }
    subunits: {
        type: '',
        geometries: [
            {type: '', id: '', arcs: [], properties: {ct: [lon, lat]}},
            // ...
        ]
    }
}

where id is the ISO-3 code for the countries layer and two-letter postal code for the subunits layer. In properties, ct is the longitude and latitude coordinates (in degrees East and degrees North respectively) of the centroid of the geometry's largest polygon in area.

Install

npm install sane-topojson