circularString

Creates a CircularString geometry from an array of points.

Circular string is a sequence of connected circular arcs, where circular arc is defined by 3 points:

• start point,
• some point on the arc,
• end point.

Circular string must have at least 3 points (one circular arc), each consecutive arc adds 2 points (arc start points is the end point from the previous arc), so the total number of points must be odd. Empty circular strings with 0 points are allowed.

Type Parameters

• P

Parameters

Name	Type	Default	Description
pts	Position[]		CircularString coordinates
options?	object		Optional geometry options
options.id?	number | string		Optional identifier to be assigned to the geometry instance.
options.properties?	P		Optional data to be assigned to the geometry instance.
options.layout?	'XY' | 'XYZ' | 'XYZM' | 'XYM'	'XYZM'	Coordinate layout for interpreting GeoJSON coordinates. Defines how to interpret the coordinates of input geometries. This does not force the dimension of the resulting geometries - the actual geometry dimension will be determined from the parsed data. Use this to: Trim unwanted Z or M ordinates from the input. Treat the third ordinate as M instead of Z.

Returns

CircularString<P>

A new CircularString geometry

Throws

• InvalidGeoJSONError if total number of points is even or equal to 1

Examples

const a = circularString([ [ 0, 0 ], [ 2, 8 ], [ 8, 0 ] ]);
// the same arc but defined by different middle point:
const b = circularString([ [ 0, 0 ], [ 6, 8 ], [ 8, 0 ] ]);

// the first point of each arc (except the 1st) is the last point from prev arc
const c = circularString([
[ 12, 4 ], [ 14, 8 ], [ 16, 4 ], // arc 1: from [ 12, 4 ] via [ 14, 8 ] to [ 16, 4 ]
           [ 18, 0 ], [ 20, 4 ], // arc 2: from [ 16, 4 ] via [ 18, 0 ] to [ 20, 4 ]
           [ 22, 8 ], [ 24, 4 ], // arc 3: from [ 20, 4 ] via [ 22, 8 ] to [ 24, 4 ]
           [ 26, 0 ], [ 28, 4 ], // arc 4: from [ 24, 4 ] via [ 26, 0 ] to [ 28, 4 ]
]);

const a = circularString([ [ 0, 0 ], [ 2, 8 ], [ 8, 0 ] ]); // the same arc but defined by different middle point: const b = circularString([ [ 0, 0 ], [ 6, 8 ], [ 8, 0 ] ]); // the first point of each arc (except the 1st) is the last point from prev arc const c = circularString([ [ 12, 4 ], [ 14, 8 ], [ 16, 4 ], // arc 1: from [ 12, 4 ] via [ 14, 8 ] to [ 16, 4 ] [ 18, 0 ], [ 20, 4 ], // arc 2: from [ 16, 4 ] via [ 18, 0 ] to [ 20, 4 ] [ 22, 8 ], [ 24, 4 ], // arc 3: from [ 20, 4 ] via [ 22, 8 ] to [ 24, 4 ] [ 26, 0 ], [ 28, 4 ], // arc 4: from [ 24, 4 ] via [ 26, 0 ] to [ 28, 4 ] ]);