geom

package module
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 Go to latest Published: Jul 18, 2017 License: BSD-2-Clause Imports: 3 Imported by: 0

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go-geom

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Package geom implements efficient geometry types for geospatial applications.

Key features

  • OpenGeo Consortium-style geometries.
  • Support for 2D and 3D geometries, measures (time and/or distance), and unlimited extra dimensions.
  • Encoding and decoding of common geometry formats (GeoJSON, KML, WKB, and others) including sql.Scanner and driver.Value interface implementations for easy database integration.
  • 2D and 3D topology functions.
  • Efficient, cache-friendly internal representation.

Detailed features

Geometry types
Encoding and decoding
Geometry functions
  • XY 2D geometry functions
  • XYZ 3D geometry functions

License

Documentation

Overview

Package geom implements efficient geometry types for geospatial applications.

Index

Examples

Constants

This section is empty.

Variables

This section is empty.

Functions

This section is empty.

Types

type Bounds 

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

A Bounds represents a multi-dimensional bounding box.

func NewBounds 

func NewBounds(layout Layout) *Bounds

NewBounds creates a new Bounds.

func (*Bounds) Clone 

func (b *Bounds) Clone() *Bounds

Clone returns a deep copy of b.

func (*Bounds) Extend 

func (b *Bounds) Extend(g T) *Bounds

Extend extends b to include geometry g.

func (*Bounds) IsEmpty 

func (b *Bounds) IsEmpty() bool

IsEmpty returns true if b is empty.

func (*Bounds) Layout 

func (b *Bounds) Layout() Layout

Layout returns b's layout.

func (*Bounds) Max 

func (b *Bounds) Max(dim int) float64

Max returns the maximum value in dimension dim.

func (*Bounds) Min 

func (b *Bounds) Min(dim int) float64

Min returns the minimum value in dimension dim.

func (*Bounds) Overlaps 

func (b *Bounds) Overlaps(layout Layout, b2 *Bounds) bool

Overlaps returns true if b overlaps b2 in layout.

func (*Bounds) OverlapsPoint 

func (b *Bounds) OverlapsPoint(layout Layout, point Coord) bool

OverlapsPoint determines if the bounding box overlaps the point (point is within or on the border of the bounds)

func (*Bounds) Set 

func (b *Bounds) Set(args ...float64) *Bounds

Set sets the minimum and maximum values. args must be an even number of values: the first half are the minimum values for each dimension and the second half are the maximum values for each dimension.

func (*Bounds) SetCoords 

func (b *Bounds) SetCoords(min, max Coord) *Bounds

SetCoords sets the minimum and maximum values of the Bounds.

type Coord 

type Coord []float64

A Coord represents an N-dimensional coordinate.

func (Coord) Clone 

func (c Coord) Clone() Coord

Clone returns a deep copy of c.

func (Coord) Equal 

func (c Coord) Equal(layout Layout, other Coord) bool

Equal compares that all ordinates are the same in this and the other coords. It is assumed that this coord and other coord both have the same (provided) layout.

func (Coord) Set 

func (c Coord) Set(other Coord)

Set copies the ordinate data from the other coord to this coord.

func (Coord) X 

func (c Coord) X() float64

X returns the x coordinate of the coordinate. X is assumed to be the first ordinate.

func (Coord) Y 

func (c Coord) Y() float64

Y returns the x coordinate of the coordinate. Y is assumed to be the second ordinate.

type ErrLayoutMismatch 

type ErrLayoutMismatch struct {
	Got  Layout
	Want Layout
}

An ErrLayoutMismatch is returned when geometries with different layouts cannot be combined.

func (ErrLayoutMismatch) Error 

func (e ErrLayoutMismatch) Error() string

type ErrStrideMismatch 

type ErrStrideMismatch struct {
	Got  int
	Want int
}

An ErrStrideMismatch is returned when the stride does not match the expected stride.

func (ErrStrideMismatch) Error 

func (e ErrStrideMismatch) Error() string

type ErrUnsupportedLayout 

type ErrUnsupportedLayout Layout

An ErrUnsupportedLayout is returned when the requested layout is not supported.

func (ErrUnsupportedLayout) Error 

func (e ErrUnsupportedLayout) Error() string

type ErrUnsupportedType 

type ErrUnsupportedType struct {
	Value interface{}
}

An ErrUnsupportedType is returned when the requested type is not supported.

func (ErrUnsupportedType) Error 

func (e ErrUnsupportedType) Error() string

type GeometryCollection 

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

A GeometryCollection is a collection of arbitrary geometries with the same SRID.

func NewGeometryCollection 

func NewGeometryCollection() *GeometryCollection

NewGeometryCollection returns a new GeometryCollection with the specified geometries.

func (*GeometryCollection) Bounds 

func (gc *GeometryCollection) Bounds() *Bounds

Bounds returns the bounds of all the geometries in gc.

func (*GeometryCollection) Empty 

func (gc *GeometryCollection) Empty() bool

Empty returns true if the collection is empty.

func (*GeometryCollection) Ends 

func (*GeometryCollection) Ends() []int

Ends panics.

func (*GeometryCollection) Endss 

func (*GeometryCollection) Endss() [][]int

Endss panics.

func (*GeometryCollection) FlatCoords 

func (*GeometryCollection) FlatCoords() []float64

FlatCoords panics.

func (*GeometryCollection) Geom 

func (gc *GeometryCollection) Geom(i int) T

Geom returns the ith geometry in gc.

func (*GeometryCollection) Geoms 

func (gc *GeometryCollection) Geoms() []T

Geoms returns the geometries in gc.

func (*GeometryCollection) Layout 

func (gc *GeometryCollection) Layout() Layout

Layout returns the smallest layout that covers all of the layouts in gc's geometries.

func (*GeometryCollection) MustPush 

func (gc *GeometryCollection) MustPush(gs ...T) *GeometryCollection

MustPush pushes gs to gc. It panics on any error.

func (*GeometryCollection) NumGeoms 

func (gc *GeometryCollection) NumGeoms() int

NumGeoms returns the number of geometries in gc.

func (*GeometryCollection) Push 

func (gc *GeometryCollection) Push(gs ...T) error

Push appends geometries.

func (*GeometryCollection) SRID 

func (gc *GeometryCollection) SRID() int

SRID returns gc's SRID.

func (*GeometryCollection) SetSRID 

func (gc *GeometryCollection) SetSRID(srid int) *GeometryCollection

SetSRID sets gc's SRID and the SRID of all its elements.

func (*GeometryCollection) Stride 

func (gc *GeometryCollection) Stride() int

Stride returns the stride of gc's layout.

type Layout 

type Layout int

A Layout describes the meaning of an N-dimensional coordinate. Layout(N) for N > 4 is a valid layout, in which case the first dimensions are interpreted to be X, Y, Z, and M and extra dimensions have no special meaning. M values are considered part of a linear referencing system (e.g. classical time or distance along a path). 1-dimensional layouts are not supported. 

const (
	// NoLayout is an unknown layout
	NoLayout Layout = iota
	// XY is a 2D layout (X and Y)
	XY
	// XYZ is 3D layout (X, Y, and Z)
	XYZ
	// XYM is a 2D layout with an M value
	XYM
	// XYZM is a 3D layout with an M value
	XYZM
)

func (Layout) MIndex 

func (l Layout) MIndex() int

MIndex returns the index of the M dimension, or -1 if the l does not have an M dimension.

func (Layout) Stride 

func (l Layout) Stride() int

Stride returns l's number of dimensions.

func (Layout) String 

func (l Layout) String() string

String returns a human-readable string representing l.

func (Layout) ZIndex 

func (l Layout) ZIndex() int

ZIndex returns the index of l's Z dimension, or -1 if l does not have a Z dimension.

type LineString 

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

A LineString represents a single, unbroken line, linearly interpreted between zero or more control points.

func NewLineString 

func NewLineString(l Layout) *LineString

NewLineString returns a new LineString with layout l and no control points.

func NewLineStringFlat 

func NewLineStringFlat(layout Layout, flatCoords []float64) *LineString

NewLineStringFlat returns a new LineString with layout l and control points flatCoords.

func (*LineString) Area 

func (ls *LineString) Area() float64

Area returns the length of ls, i.e. zero.

func (*LineString) Clone 

func (ls *LineString) Clone() *LineString

Clone returns a copy of ls that does not alias ls.

func (*LineString) Coord 

func (g *LineString) Coord(i int) Coord

func (*LineString) Coords 

func (g *LineString) Coords() []Coord

func (*LineString) Empty 

func (ls *LineString) Empty() bool

Empty returns false.

func (*LineString) Interpolate 

func (ls *LineString) Interpolate(val float64, dim int) (int, float64)

Interpolate returns the index and delta of val in dimension dim.

func (*LineString) Length 

func (ls *LineString) Length() float64

Length returns the length of ls.

func (*LineString) MustSetCoords 

func (ls *LineString) MustSetCoords(coords []Coord) *LineString

MustSetCoords is like SetCoords but it panics on any error.

func (*LineString) NumCoords 

func (g *LineString) NumCoords() int

func (*LineString) SetCoords 

func (ls *LineString) SetCoords(coords []Coord) (*LineString, error)

SetCoords sets the coordinates of ls.

func (*LineString) SetSRID 

func (ls *LineString) SetSRID(srid int) *LineString

SetSRID sets the SRID of ls.

func (*LineString) SubLineString 

func (ls *LineString) SubLineString(start, stop int) *LineString

SubLineString returns a LineString from starts at index start and stops at index stop of ls. The returned LineString aliases ls.

func (*LineString) Swap 

func (ls *LineString) Swap(ls2 *LineString)

Swap swaps the values of ls and ls2.

type LinearRing 

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

A LinearRing is a linear ring.

func NewLinearRing 

func NewLinearRing(layout Layout) *LinearRing

NewLinearRing returns a new LinearRing with no coordinates.

func NewLinearRingFlat 

func NewLinearRingFlat(layout Layout, flatCoords []float64) *LinearRing

NewLinearRingFlat returns a new LinearRing with the given flat coordinates.

func (*LinearRing) Area 

func (lr *LinearRing) Area() float64

Area returns the the area.

func (*LinearRing) Clone 

func (lr *LinearRing) Clone() *LinearRing

Clone returns a deep copy.

func (*LinearRing) Coord 

func (g *LinearRing) Coord(i int) Coord

func (*LinearRing) Coords 

func (g *LinearRing) Coords() []Coord

func (*LinearRing) Empty 

func (lr *LinearRing) Empty() bool

Empty returns false.

func (*LinearRing) Length 

func (lr *LinearRing) Length() float64

Length returns the length of the perimeter.

func (*LinearRing) MustSetCoords 

func (lr *LinearRing) MustSetCoords(coords []Coord) *LinearRing

MustSetCoords sets the coordinates and panics if there is any error.

func (*LinearRing) NumCoords 

func (g *LinearRing) NumCoords() int

func (*LinearRing) SetCoords 

func (lr *LinearRing) SetCoords(coords []Coord) (*LinearRing, error)

SetCoords sets the coordinates.

func (*LinearRing) SetSRID 

func (lr *LinearRing) SetSRID(srid int) *LinearRing

SetSRID sets the SRID of lr.

func (*LinearRing) Swap 

func (lr *LinearRing) Swap(lr2 *LinearRing)

Swap swaps the values of lr and lr2.

type MultiLineString 

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

A MultiLineString is a collection of LineStrings.

func NewMultiLineString 

func NewMultiLineString(layout Layout) *MultiLineString

NewMultiLineString returns a new MultiLineString with no LineStrings.

func NewMultiLineStringFlat 

func NewMultiLineStringFlat(layout Layout, flatCoords []float64, ends []int) *MultiLineString

NewMultiLineStringFlat returns a new MultiLineString with the given flat coordinates.

func (*MultiLineString) Area 

func (mls *MultiLineString) Area() float64

Area returns 0.

func (*MultiLineString) Clone 

func (mls *MultiLineString) Clone() *MultiLineString

Clone returns a deep copy.

func (*MultiLineString) Coords 

func (g *MultiLineString) Coords() [][]Coord

func (*MultiLineString) Empty 

func (mls *MultiLineString) Empty() bool

Empty returns true if the collection is empty.

func (*MultiLineString) Ends 

func (g *MultiLineString) Ends() []int

func (*MultiLineString) Length 

func (mls *MultiLineString) Length() float64

Length returns the sum of the length of the LineStrings.

func (*MultiLineString) LineString 

func (mls *MultiLineString) LineString(i int) *LineString

LineString returns the ith LineString.

func (*MultiLineString) MustSetCoords 

func (mls *MultiLineString) MustSetCoords(coords [][]Coord) *MultiLineString

MustSetCoords sets the coordinates and panics on any error.

func (*MultiLineString) NumLineStrings 

func (mls *MultiLineString) NumLineStrings() int

NumLineStrings returns the number of LineStrings.

func (*MultiLineString) Push 

func (mls *MultiLineString) Push(ls *LineString) error

Push appends a LineString.

func (*MultiLineString) SetCoords 

func (mls *MultiLineString) SetCoords(coords [][]Coord) (*MultiLineString, error)

SetCoords sets the coordinates.

func (*MultiLineString) SetSRID 

func (mls *MultiLineString) SetSRID(srid int) *MultiLineString

SetSRID sets the SRID of mls.

func (*MultiLineString) Swap 

func (mls *MultiLineString) Swap(mls2 *MultiLineString)

Swap swaps the values of mls and mls2.

type MultiPoint 

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

A MultiPoint is a collection of Points.

func NewMultiPoint 

func NewMultiPoint(layout Layout) *MultiPoint

NewMultiPoint returns a new, empty, MultiPoint.

func NewMultiPointFlat 

func NewMultiPointFlat(layout Layout, flatCoords []float64) *MultiPoint

NewMultiPointFlat returns a new MultiPoint with the given flat coordinates.

func (*MultiPoint) Area 

func (mp *MultiPoint) Area() float64

Area returns zero.

func (*MultiPoint) Clone 

func (mp *MultiPoint) Clone() *MultiPoint

Clone returns a deep copy.

func (*MultiPoint) Coord 

func (g *MultiPoint) Coord(i int) Coord

func (*MultiPoint) Coords 

func (g *MultiPoint) Coords() []Coord

func (*MultiPoint) Empty 

func (mp *MultiPoint) Empty() bool

Empty returns true if the collection is empty.

func (*MultiPoint) Length 

func (mp *MultiPoint) Length() float64

Length returns zero.

func (*MultiPoint) MustSetCoords 

func (mp *MultiPoint) MustSetCoords(coords []Coord) *MultiPoint

MustSetCoords sets the coordinates and panics on any error.

func (*MultiPoint) NumCoords 

func (g *MultiPoint) NumCoords() int

func (*MultiPoint) NumPoints 

func (mp *MultiPoint) NumPoints() int

NumPoints returns the number of Points.

func (*MultiPoint) Point 

func (mp *MultiPoint) Point(i int) *Point

Point returns the ith Point.

func (*MultiPoint) Push 

func (mp *MultiPoint) Push(p *Point) error

Push appends a point.

func (*MultiPoint) SetCoords 

func (mp *MultiPoint) SetCoords(coords []Coord) (*MultiPoint, error)

SetCoords sets the coordinates.

func (*MultiPoint) SetSRID 

func (mp *MultiPoint) SetSRID(srid int) *MultiPoint

SetSRID sets the SRID of mp.

func (*MultiPoint) Swap 

func (mp *MultiPoint) Swap(mp2 *MultiPoint)

Swap swaps the values of mp and mp2.

type MultiPolygon 

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

A MultiPolygon is a collection of Polygons.

func NewMultiPolygon 

func NewMultiPolygon(layout Layout) *MultiPolygon

NewMultiPolygon returns a new MultiPolygon with no Polygons.

func NewMultiPolygonFlat 

func NewMultiPolygonFlat(layout Layout, flatCoords []float64, endss [][]int) *MultiPolygon

NewMultiPolygonFlat returns a new MultiPolygon with the given flat coordinates.

func (*MultiPolygon) Area 

func (mp *MultiPolygon) Area() float64

Area returns the sum of the area of the individual Polygons.

func (*MultiPolygon) Clone 

func (mp *MultiPolygon) Clone() *MultiPolygon

Clone returns a deep copy.

func (*MultiPolygon) Coords 

func (g *MultiPolygon) Coords() [][][]Coord

func (*MultiPolygon) Empty 

func (mp *MultiPolygon) Empty() bool

Empty returns true if the collection is empty.

func (*MultiPolygon) Endss 

func (g *MultiPolygon) Endss() [][]int

func (*MultiPolygon) Length 

func (mp *MultiPolygon) Length() float64

Length returns the sum of the perimeters of the Polygons.

func (*MultiPolygon) MustSetCoords 

func (mp *MultiPolygon) MustSetCoords(coords [][][]Coord) *MultiPolygon

MustSetCoords sets the coordinates and panics on any error.

func (*MultiPolygon) NumPolygons 

func (mp *MultiPolygon) NumPolygons() int

NumPolygons returns the number of Polygons.

func (*MultiPolygon) Polygon 

func (mp *MultiPolygon) Polygon(i int) *Polygon

Polygon returns the ith Polygon.

func (*MultiPolygon) Push 

func (mp *MultiPolygon) Push(p *Polygon) error

Push appends a Polygon.

func (*MultiPolygon) SetCoords 

func (mp *MultiPolygon) SetCoords(coords [][][]Coord) (*MultiPolygon, error)

SetCoords sets the coordinates.

func (*MultiPolygon) SetSRID 

func (mp *MultiPolygon) SetSRID(srid int) *MultiPolygon

SetSRID sets the SRID of mp.

func (*MultiPolygon) Swap 

func (mp *MultiPolygon) Swap(mp2 *MultiPolygon)

Swap swaps the values of mp and mp2.

type Point 

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

A Point represents a single point.

func NewPoint 

func NewPoint(l Layout) *Point

NewPoint allocates a new Point with layout l and all values zero.

func NewPointFlat 

func NewPointFlat(l Layout, flatCoords []float64) *Point

NewPointFlat allocates a new Point with layout l and flat coordinates flatCoords.

func (*Point) Area 

func (p *Point) Area() float64

Area returns p's area, i.e. zero.

func (*Point) Bounds 

func (g *Point) Bounds() *Bounds

func (*Point) Clone 

func (p *Point) Clone() *Point

Clone returns a copy of p that does not alias p.

func (*Point) Coords 

func (g *Point) Coords() Coord

func (*Point) Empty 

func (p *Point) Empty() bool

Empty returns false.

func (*Point) Ends 

func (g *Point) Ends() []int

func (*Point) Endss 

func (g *Point) Endss() [][]int

func (*Point) FlatCoords 

func (g *Point) FlatCoords() []float64

func (*Point) Layout 

func (g *Point) Layout() Layout

func (*Point) Length 

func (p *Point) Length() float64

Length returns the length of p, i.e. zero.

func (*Point) M 

func (p *Point) M() float64

M returns p's M-coordinate, or zero if p has no M-coordinate.

func (*Point) MustSetCoords 

func (p *Point) MustSetCoords(coords Coord) *Point

MustSetCoords is like SetCoords but panics on any error.

func (*Point) NumCoords 

func (g *Point) NumCoords() int

func (*Point) Reserve 

func (g *Point) Reserve(n int)

func (*Point) SRID 

func (g *Point) SRID() int

func (*Point) SetCoords 

func (p *Point) SetCoords(coords Coord) (*Point, error)

SetCoords sets the coordinates of p.

func (*Point) SetSRID 

func (p *Point) SetSRID(srid int) *Point

SetSRID sets the SRID of p.

func (*Point) Stride 

func (g *Point) Stride() int

func (*Point) Swap 

func (p *Point) Swap(p2 *Point)

Swap swaps the values of p and p2.

func (*Point) X 

func (p *Point) X() float64

X returns p's X-coordinate.

func (*Point) Y 

func (p *Point) Y() float64

Y returns p's Y-coordinate.

func (*Point) Z 

func (p *Point) Z() float64

Z returns p's Z-coordinate, or zero if p has no Z-coordinate.

type Polygon 

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

A Polygon represents a polygon as a collection of LinearRings. The first LinearRing is the outer boundary. Subsequent LinearRings are inner boundaries (holes).

func NewPolygon 

func NewPolygon(layout Layout) *Polygon

NewPolygon returns a new, empty, Polygon.

Example 
unitSquare := NewPolygon(XY).MustSetCoords([][]Coord{
	{{0, 0}, {1, 0}, {1, 1}, {0, 1}, {0, 0}},
})
fmt.Printf("unitSquare.Area() == %f", unitSquare.Area())

Output:

unitSquare.Area() == 1.000000

func NewPolygonFlat 

func NewPolygonFlat(layout Layout, flatCoords []float64, ends []int) *Polygon

NewPolygonFlat returns a new Polygon with the given flat coordinates.

func (*Polygon) Area 

func (p *Polygon) Area() float64

Area returns the area.

func (*Polygon) Clone 

func (p *Polygon) Clone() *Polygon

Clone returns a deep copy.

func (*Polygon) Coords 

func (g *Polygon) Coords() [][]Coord

func (*Polygon) Empty 

func (p *Polygon) Empty() bool

Empty returns false.

func (*Polygon) Ends 

func (g *Polygon) Ends() []int

func (*Polygon) Length 

func (p *Polygon) Length() float64

Length returns the perimter.

func (*Polygon) LinearRing 

func (p *Polygon) LinearRing(i int) *LinearRing

LinearRing returns the ith LinearRing.

func (*Polygon) MustSetCoords 

func (p *Polygon) MustSetCoords(coords [][]Coord) *Polygon

MustSetCoords sets the coordinates and panics on any error.

func (*Polygon) NumLinearRings 

func (p *Polygon) NumLinearRings() int

NumLinearRings returns the number of LinearRings.

func (*Polygon) Push 

func (p *Polygon) Push(lr *LinearRing) error

Push appends a LinearRing.

func (*Polygon) SetCoords 

func (p *Polygon) SetCoords(coords [][]Coord) (*Polygon, error)

SetCoords sets the coordinates.

func (*Polygon) SetSRID 

func (p *Polygon) SetSRID(srid int) *Polygon

SetSRID sets the SRID of p.

func (*Polygon) Swap 

func (p *Polygon) Swap(p2 *Polygon)

Swap swaps the values of p and p2.

type T 

type T interface {
	Layout() Layout
	Stride() int
	Bounds() *Bounds
	FlatCoords() []float64
	Ends() []int
	Endss() [][]int
	SRID() int
}

T is a generic interface implemented by all geometry types.

func Must 

func Must(g T, err error) T

Must panics if err is not nil, otherwise it returns g.

Source Files

View all Source files

Directories

Path Synopsis
Package bigxy contains robust geographic functions on planar (xy) data.
 Package bigxy contains robust geographic functions on planar (xy) data.
encoding
ewkb
Package ewkb implements Extended Well Known Binary encoding and decoding.
 Package ewkb implements Extended Well Known Binary encoding and decoding.
ewkbhex
Package ewkbhex implements Extended Well Known Binary encoding and decoding of strings.
 Package ewkbhex implements Extended Well Known Binary encoding and decoding of strings.
geojson
Package geojson implements GeoJSON encoding and decoding.
 Package geojson implements GeoJSON encoding and decoding.
igc
Package igc implements an IGC parser.
 Package igc implements an IGC parser.
igc/cmd/igc2kml
kml
Package kml implements KML encoding.
 Package kml implements KML encoding.
wkb
Package wkb implements Well Known Binary encoding and decoding.
 Package wkb implements Well Known Binary encoding and decoding.
wkbcommon
Package wkbcommon contains code common to WKB and EWKB encoding.
 Package wkbcommon contains code common to WKB and EWKB encoding.
wkbhex
Package wkbhex implements Well Known Binary encoding and decoding of strings.
 Package wkbhex implements Well Known Binary encoding and decoding of strings.
wkt
xy
Package xy contains low-level planar (xy) geographic functions.
 Package xy contains low-level planar (xy) geographic functions.
internal
internal/centralendpoint
internal/hcoords
internal/lineintersector
lineintersection
location
orientation
Package xyz contains operations in 3d coordinate space.
 Package xyz contains operations in 3d coordinate space.

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