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DGGS Function Libraries

From-v4.2Experimental

Import optional Discrete Global Grid System function tables from @math.gl/expressions/dggs.

import {ExpressionFunctionRegistry, compile} from '@math.gl/expressions';
import {DGGS_FUNCTION_LIBRARY} from '@math.gl/expressions/dggs';

const registry = new ExpressionFunctionRegistry([DGGS_FUNCTION_LIBRARY]);
const evaluate = compile('getGeohashBoundary(hash)', {registry});

evaluate({hash: '9q8yy'});

GEOHASH_FUNCTION_LIBRARY​

  • getGeohashLngLat
  • getGeohashBounds
  • getGeohashBoundary
  • getGeohashBoundaryFlat

QUADKEY_FUNCTION_LIBRARY​

  • getQuadkeyLngLat
  • quadkeyToWorldBounds
  • getQuadkeyBoundary
  • getQuadkeyBoundaryFlat

S2_FUNCTION_LIBRARY​

  • getS2IndexFromToken
  • getS2TokenFromIndex
  • getS2ChildIndex
  • getS2BoundaryFlat

S2 index functions use JavaScript bigint values.

DGGS_FUNCTION_LIBRARY​

Combines the GeoHash, Quadkey, and S2 tables into one registration-ready table.

The individual constants allow applications to include only the DGGS systems they expose to expressions.