geo

package module
v0.0.2 Latest Latest
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 Go to latest Published: Mar 3, 2023 License: Apache-2.0 Imports: 9 Imported by: 2

README

geo_fencer

Geo fence library

Documentation

Index

Constants

View Source 
const (
	EarthRad = 6372800 //meters
	RadToDeg = 180 / math.Pi
	DegToRad = math.Pi / 180
)
View Source 
const Dim = 2

Variables

View Source 
var (
	RtreeMinChildren = 25
	RtreeMaxChildren = 50
)

Functions

func UnmarshalGeojsonFeature 

func UnmarshalGeojsonFeature(raw string) (feature *geojson.Feature, err error)

Types

type Box 

type Box struct {
	// contains filtered or unexported fields
}

func NewBox 

func NewBox(min, max Coordinate) (box Box, err error)

func (Box) Contains 

func (b Box) Contains(coords ...Coordinate) (in bool)

func (Box) NorthEast 

func (b Box) NorthEast() Coordinate

func (Box) SouthWest 

func (b Box) SouthWest() Coordinate

type Coordinate 

type Coordinate struct {
	Lat, Lon float64
}

func (Coordinate) Difference 

func (c Coordinate) Difference(o Coordinate) (d Coordinate)

func (Coordinate) Distance 

func (cd Coordinate) Distance(od Coordinate) float64

Distance between coordinates in meters

func (Coordinate) String 

func (c Coordinate) String() string

func (Coordinate) ToRad 

func (c Coordinate) ToRad() Coordinate

func (Coordinate) X 

func (c Coordinate) X() float64

func (Coordinate) Y 

func (c Coordinate) Y() float64

type DistError 

type DistError float64

DistError is an improper distance measurement. It implements the error and is generated when a distance-related assertion fails.

func (DistError) Error 

func (err DistError) Error() string

type Feature 

type Feature struct {
	ID         interface{}
	Geometry   []*Shape
	Type       string
	Properties map[string]interface{}
}

func GeojsonFeatureAdapter 

func GeojsonFeatureAdapter(gj *geojson.Feature) (feature *Feature, err error)

Flatten all the points of a feature into single list. This can hel in identifying which tiles are going to be created

func MakeFeature 

func MakeFeature(length int) *Feature

func NewFeature 

func NewFeature(geometryType string, geometry ...*Shape) *Feature

func NewLineFeature 

func NewLineFeature(geometry ...*Shape) *Feature

func NewPointFeature 

func NewPointFeature(geometry ...*Shape) *Feature

func NewPolygonFeature 

func NewPolygonFeature(geometry ...*Shape) *Feature

func (*Feature) AddShape 

func (f *Feature) AddShape(s *Shape)

func (*Feature) Center 

func (f *Feature) Center() (avg Coordinate)

func (*Feature) Contains 

func (f *Feature) Contains(c Coordinate) bool

Only checks as exterior ring

func (*Feature) Tags 

func (f *Feature) Tags(key string) string

type GeojsonSource 

type GeojsonSource struct {
	// contains filtered or unexported fields
}

func NewGeojsonSource 

func NewGeojsonSource(path string, filter []string) *GeojsonSource

func (*GeojsonSource) Publish 

func (gj *GeojsonSource) Publish() (features chan *Feature, err error)

type GeometryType 

type GeometryType string
const (
	PolygonFeature GeometryType = "polygon"
	LineFeature    GeometryType = "line"
	PointFeature   GeometryType = "point"
)

type Point 

type Point [Dim]float64

Point represents a point in 3-dimensional Euclidean space.

func (Point) ToRect 

func (p Point) ToRect(tol float64) *Rect

ToRect constructs a rectangle containing p with side lengths 2*tol.

type Rect 

type Rect struct {
	// contains filtered or unexported fields
}

Rect represents a subset of 3-dimensional Euclidean space of the form [a1, b1] x [a2, b2] x ... x [an, bn], where ai < bi for all 1 <= i <= n.

func NewRect 

func NewRect(p Point, lengths [Dim]float64) (r Rect, err error)

NewRect constructs and returns a pointer to a Rect given a corner point and the lengths of each dimension. The point p should be the most-negative point on the rectangle (in every dimension) and every length should be positive.

func (*Rect) String 

func (r *Rect) String() string

type Rnode 

type Rnode struct {
	// contains filtered or unexported fields
}

func NewRnode 

func NewRnode(shape *Shape, data interface{}) *Rnode

func (*Rnode) Bounds 

func (n *Rnode) Bounds() *Rect

implements rtree.Spatial

func (*Rnode) Feature 

func (n *Rnode) Feature() *Feature

func (*Rnode) Value 

func (n *Rnode) Value() interface{}

type Rtree 

type Rtree struct {
	MinChildren int
	MaxChildren int
	// contains filtered or unexported fields
}

Rtree represents an R-tree, a balanced search tree for storing and querying spatial objects. MinChildren/MaxChildren specify the minimum/maximum branching factors.

func NewRtree 

func NewRtree() *Rtree

func NewTree 

func NewTree(MinChildren, MaxChildren int) *Rtree

NewTree creates a new R-tree instance.

func (*Rtree) Contains 

func (r *Rtree) Contains(c Coordinate) []*Rnode

func (*Rtree) Delete 

func (tree *Rtree) Delete(obj Spatial) bool

Delete removes an object from the tree. If the object is not found, ok is false; otherwise ok is true.

Implemented per Section 3.3 of "R-trees: A Dynamic Index Structure for Spatial Searching" by A. Guttman, Proceedings of ACM SIGMOD, p. 47-57, 1984.

func (*Rtree) Depth 

func (tree *Rtree) Depth() int

Depth returns the maximum depth of tree.

func (*Rtree) Insert 

func (tree *Rtree) Insert(obj Spatial)

Insert inserts a spatial object into the tree. If insertion causes a leaf node to overflow, the tree is rebalanced automatically.

Implemented per Section 3.2 of "R-trees: A Dynamic Index Structure for Spatial Searching" by A. Guttman, Proceedings of ACM SIGMOD, p. 47-57, 1984.

func (*Rtree) Intersections 

func (r *Rtree) Intersections(q *Shape) []*Rnode

func (*Rtree) NearestNeighbor 

func (tree *Rtree) NearestNeighbor(p Point) Spatial

NearestNeighbor returns the closest object to the specified point. Implemented per "Nearest Neighbor Queries" by Roussopoulos et al

func (*Rtree) NearestNeighbors 

func (tree *Rtree) NearestNeighbors(k int, p Point) []Spatial

func (*Rtree) SearchIntersect 

func (tree *Rtree) SearchIntersect(bb *Rect) []Spatial

SearchIntersectBB returns all objects that intersect the specified rectangle.

Implemented per Section 3.1 of "R-trees: A Dynamic Index Structure for Spatial Searching" by A. Guttman, Proceedings of ACM SIGMOD, p. 47-57, 1984.

func (*Rtree) Size 

func (tree *Rtree) Size() int

Size returns the number of objects currently stored in tree.

func (*Rtree) String 

func (tree *Rtree) String() string

type Shape 

type Shape struct {
	Coordinates []Coordinate
}

func MakeShape 

func MakeShape(length int) *Shape

func NewShape 

func NewShape(coords ...Coordinate) *Shape

func ShapeFromString 

func ShapeFromString(raw string) (shp *Shape, err error)

[[lon,lat]...]

func (*Shape) Add 

func (s *Shape) Add(c ...Coordinate)

func (*Shape) Append 

func (s *Shape) Append(o *Shape)

func (*Shape) BoundingBox 

func (s *Shape) BoundingBox() Box

func (*Shape) Contains 

func (s *Shape) Contains(c Coordinate) bool

func (*Shape) Edges 

func (s *Shape) Edges() <-chan []Coordinate

func (*Shape) Head 

func (s *Shape) Head() Coordinate

func (*Shape) IsClockwise 

func (s *Shape) IsClockwise() bool

func (*Shape) IsClosed 

func (s *Shape) IsClosed() bool

Only shapes that contain an area can be closed (>3 Coordinates)

func (*Shape) Length 

func (s *Shape) Length() int

Number of coordinates

func (*Shape) Reverse 

func (s *Shape) Reverse()

func (*Shape) Tail 

func (s *Shape) Tail() Coordinate

type Spatial 

type Spatial interface {
	Bounds() *Rect
}

Any type that implements Spatial can be stored in an Rtree and queried.

Source Files

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