osm

Documentation

Overview

Package osm extracts and manipulates OpenStreetMap (OSM) data. Refer to openstreetmap.org for more information about OSM data.

Index

• type Data
  • func ExtractTag(rs io.ReadSeeker, tag string, values ...string) (*Data, error)
  • func (o *Data) Check() error
  • func (o *Data) Geom() ([]*GeomTags, error)
• type GeomTags
• type GeomType
  • func DominantType(gt []*GeomTags) (GeomType, error)
• type ObjectType
• type TagCount
  • func (t *TagCount) DominantType() ObjectType
• type Tags
  • func CountTags(rs io.ReadSeeker) (Tags, error)
  • func (t *Tags) Filter(f func(*TagCount) bool) *Tags
  • func (t *Tags) Len() int
  • func (t *Tags) Less(i, j int) bool
  • func (t *Tags) Swap(i, j int)
  • func (t *Tags) Table() [][]string

Types

type Data

type Data struct {
	Nodes     map[int64]*osmpbf.Node
	Ways      map[int64]*osmpbf.Way
	Relations map[int64]*osmpbf.Relation
	// contains filtered or unexported fields
}

Data holds OpenStreetMap data and relationships.

func ExtractTag

func ExtractTag(rs io.ReadSeeker, tag string, values ...string) (*Data, error)

ExtractTag extracts OpenStreetMap data with the given tag set to one of the given values.

func (*Data) Check

func (o *Data) Check() error

Check checks OSM data to ensure that all necessary components are present.

func (*Data) Geom

func (o *Data) Geom() ([]*GeomTags, error)

Geom converts the OSM data to geometry objects, keeping the tag information.

type GeomTags

type GeomTags struct {
	geom.Geom
	Tags map[string]string
}

GeomTags holds a geometry object and the tags that apply to it.

type GeomType

type GeomType int

const (
	Point GeomType = iota
	Line
	Poly
	Collection
)

func DominantType

func DominantType(gt []*GeomTags) (GeomType, error)

DominantType returns the most frequently occurring type among the given features.

type ObjectType

type ObjectType int

ObjectType specifies the valid OpenStreetMap types.

const (
	// Node is an OpenStreetMap node.
	Node ObjectType = iota
	// ClosedWay is an OpenStreetMap way that is closed (i.e., a polygon).
	ClosedWay
	// OpenWay is an OpenStreetMap way that is open (i.e., a line string).
	OpenWay
	// Relation is an OpenStreetMap relation.
	Relation
)

type TagCount

type TagCount struct {
	Key, Value  string
	ObjectCount map[ObjectType]int
	TotalCount  int
}

TagCount hold information about the number of instances of the specified tag in a database.

func (*TagCount) DominantType

func (t *TagCount) DominantType() ObjectType

DominantType returns the most frequently occuring ObjectType for this tag.

type Tags

type Tags []*TagCount

Tags holds information about the tags that are in a database.

func CountTags

func CountTags(rs io.ReadSeeker) (Tags, error)

CountTags returns the different tags in the database and the number of instances of each one.

func (*Tags) Filter

func (t *Tags) Filter(f func(*TagCount) bool) *Tags

Filter applies function f to all records in the receiver and returns a copy of the receiver that only contains the records for which f returns true.

func (*Tags) Len

func (t *Tags) Len() int

Len returns the length of the receiver to implement the sort.Sort interface.

func (*Tags) Less

func (t *Tags) Less(i, j int) bool

Less returns whether item i is less than item j to implement the sort.Sort interface.

func (*Tags) Swap

func (t *Tags) Swap(i, j int)

Swap swaps elements i and j to implement the sort.Sort interface.

func (*Tags) Table

func (t *Tags) Table() [][]string

Table creates a table of the information held by the receiver.