This package implements several reducing/simplifing function for orb.Geometry types.
Currently implemented:
Note: The geometry object CAN be modified, use Clone() if a copy is required.
Probably the most popular simplification algorithm. For algorithm details, see wikipedia.
The algorithm is a pass through for 1d geometry, e.g. Point and MultiPoint.
The algorithms can modify the original geometry, use Clone() if a copy is required.
Usage:
original := orb.LineString{}
reduced := simplify.DouglasPeucker(threshold).Simplify(original.Clone())
See Mike Bostock's explanation for algorithm details.
The algorithm is a pass through for 1d geometry, e.g. Point and MultiPoint.
The algorithms can modify the original geometry, use Clone() if a copy is required.
Usage:
original := orb.Ring{}
// will remove all whose triangle is smaller than `threshold`
reduced := simplify.VisvalingamThreshold(threshold).Simplify(original)
// will remove points until there are only `toKeep` points left.
reduced := simplify.VisvalingamKeep(toKeep).Simplify(original)
// One can also combine the parameters.
// This will continue to remove points until:
// - there are no more below the threshold,
// - or the new path is of length `toKeep`
reduced := simplify.Visvalingam(threshold, toKeep).Simplify(original)
Radial reduces the path by removing points that are close together. A full algorithm description.
The algorithm is a pass through for 1d geometry, like Point and MultiPoint.
The algorithms can modify the original geometry, use Clone() if a copy is required.
Usage:
original := geo.Polygon{}
// this method uses a Euclidean distance measure.
reduced := simplify.Radial(planar.Distance, threshold).Simplify(path)
// if the points are in the lng/lat space Radial Geo will
// compute the geo distance between the coordinates.
reduced:= simplify.Radial(geo.Distance, meters).Simplify(path)