Subgroup: Geometry

Class: QgsGeometry

class qgis.core.QgsGeometry

Bases: sip.wrapper

Constructor

QgsGeometry(QgsGeometry) Copy constructor will prompt a deep copy of the object

QgsGeometry(geom: QgsAbstractGeometry) Creates a geometry from an abstract geometry object. Ownership of geom is transferred.

New in version 2.10.

A geometry is the spatial representation of a feature. Since QGIS 2.10, QgsGeometry acts as a generic container for geometry objects. QgsGeometry is implicitly shared, so making copies of geometries is inexpensive. The geometry container class can also be stored inside a QVariant object.

The actual geometry representation is stored as a QgsAbstractGeometry within the container, and can be accessed via the geometry() method or set using the setGeometry() method.

Methods

addPart Adds a new part to this geometry.
addPartGeometry Adds a new island polygon to a multipolygon feature
addPoints Adds a new part to a the geometry.
addPointsXY Adds a new part to a the geometry.
addRing Adds a new ring to this geometry.
adjacentVertices Returns the indexes of the vertices before and after the given vertex index.
angleAtVertex Returns the bisector angle for this geometry at the specified vertex.
area Returns the area of the geometry using GEOS
asGeometryCollection Returns contents of the geometry as a list of geometries
asJson Exports the geometry to a GeoJSON string.
asMultiPoint Returns contents of the geometry as a multi point if wkbType is WKBMultiPoint, otherwise an empty list
asMultiPolygon Returns contents of the geometry as a multi polygon if wkbType is WKBMultiPolygon, otherwise an empty list
asMultiPolyline Returns contents of the geometry as a multi linestring if wkbType is WKBMultiLineString, otherwise an empty list
asPoint Returns contents of the geometry as a point if wkbType is WKBPoint, otherwise returns [0,0]
asPolygon Returns contents of the geometry as a polygon if wkbType is WKBPolygon, otherwise an empty list
asPolyline Returns contents of the geometry as a polyline if wkbType is WKBLineString, otherwise an empty list
asQPointF Returns contents of the geometry as a QPointF if wkbType is WKBPoint, otherwise returns a null QPointF.
asQPolygonF Returns contents of the geometry as a QPolygonF.
asWkb Export the geometry to WKB
asWkt Exports the geometry to WKT
avoidIntersections Modifies geometry to avoid intersections with the layers specified in project properties
boundingBox Returns the bounding box of the geometry.
boundingBoxIntersects Returns true if the bounding box of this geometry intersects with a rectangle.
buffer Returns a buffer region around this geometry having the given width and with a specified number of segments used to approximate curves
centroid Returns the center of mass of a geometry.
clipped Clips the geometry using the specified rectangle.
closestSegmentWithContext Searches for the closest segment of geometry to the given point
closestVertex
closestVertexWithContext Searches for the closest vertex in this geometry to the given point.
collectGeometry Creates a new multipart geometry from a list of QgsGeometry objects
combine Returns a geometry representing all the points in this geometry and other (a union geometry operation).
compare Compares two geometry objects for equality within a specified tolerance.
constGet Returns a non-modifiable (const) reference to the underlying abstract geometry primitive.
contains Tests for containment of a point (uses GEOS)
convertGeometryCollectionToSubclass Converts geometry collection to a the desired geometry type subclass (multi-point, multi-linestring or multi-polygon).
convertPointList Upgrades a point list from QgsPointXY to QgsPoint
convertToMultiType Converts single type geometry into multitype geometry e.g.
convertToSingleType Converts multi type geometry into single type geometry e.g.
convertToStraightSegment Converts the geometry to straight line segments, if it is a curved geometry type.
convertToType Try to convert the geometry to the requested type
convexHull Returns the smallest convex polygon that contains all the points in the geometry.
createGeometryEngine Creates and returns a new geometry engine
createPolygonFromQPolygonF Creates a QgsPolygonXYfrom a QPolygonF.
createPolylineFromQPolygonF Creates a QgsPolylineXY from a QPolygonF.
createWedgeBuffer Creates a wedge shaped buffer from a center point.
crosses Test for if geometry crosses another (uses GEOS)
delaunayTriangulation Returns the Delaunay triangulation for the vertices of the geometry.
deletePart Deletes part identified by the part number
deleteRing Deletes a ring in polygon or multipolygon.
deleteVertex Deletes the vertex at the given position number and item (first number is index 0)
densifyByCount Returns a copy of the geometry which has been densified by adding the specified number of extra nodes within each segment of the geometry.
densifyByDistance Densifies the geometry by adding regularly placed extra nodes inside each segment so that the maximum distance between any two nodes does not exceed the specified distance.
difference Returns a geometry representing the points making up this geometry that do not make up other.
disjoint Tests for if geometry is disjoint of another (uses GEOS)
distance Returns the minimum distance between this geometry and another geometry, using GEOS.
distanceToVertex Returns the distance along this geometry from its first vertex to the specified vertex.
draw Draws the geometry onto a QPainter
equals Test if this geometry is exactly equal to another geometry.
extendLine Extends a (multi)line geometry by extrapolating out the start or end of the line by a specified distance.
extrude Returns an extruded version of this geometry.
fromMultiPointXY Creates a new geometry from a QgsMultiPointXY object
fromMultiPolygonXY Creates a new geometry from a QgsMultiPolygon
fromMultiPolylineXY Creates a new geometry from a QgsMultiPolylineXY object
fromPointXY Creates a new geometry from a QgsPointXY object
fromPolygonXY Creates a new geometry from a QgsPolygon
fromPolyline Creates a new LineString geometry from a list of QgsPoint points.
fromPolylineXY Creates a new LineString geometry from a list of QgsPointXY points.
fromQPointF Construct geometry from a QPointF
fromQPolygonF Construct geometry from a QPolygonF.
fromRect Creates a new geometry from a QgsRectangle
fromWkb Set the geometry, feeding in the buffer containing OGC Well-Known Binary
fromWkt Creates a new geometry from a WKT string
get Returns a modifiable (non-const) reference to the underlying abstract geometry primitive.
hausdorffDistance Returns the Hausdorff distance between this geometry and geom.
hausdorffDistanceDensify Returns the Hausdorff distance between this geometry and geom.
insertVertex Insert a new vertex before the given vertex index, ring and item (first number is index 0) If the requested vertex number (beforeVertex.back()) is greater than the last actual vertex on the requested ring and item, it is assumed that the vertex is to be appended instead of inserted.
interpolate Returns an interpolated point on the geometry at the specified distance.
interpolateAngle Returns the angle parallel to the linestring or polygon boundary at the specified distance along the geometry.
intersection Returns a geometry representing the points shared by this geometry and other.
intersects Returns true if this geometry exactly intersects with a rectangle.
isEmpty Returns true if the geometry is empty (eg a linestring with no vertices, or a collection with no geometries).
isGeosEqual Compares the geometry with another geometry using GEOS.
isGeosValid Checks validity of the geometry using GEOS
isMultipart Returns true if WKB of the geometry is of WKBMulti* type
isNull Returns true if the geometry is null (ie, contains no underlying geometry accessible via geometry() ).
isSimple Determines whether the geometry is simple (according to OGC definition), i.e.
lastError Returns an error string referring to the last error encountered either when this geometry was created or when an operation was performed on the geometry.
length Returns the length of geometry using GEOS
lineLocatePoint Returns a distance representing the location along this linestring of the closest point on this linestring geometry to the specified point.
makeDifference Returns the geometry formed by modifying this geometry such that it does not intersect the other geometry.
makeValid Attempts to make an invalid geometry valid without losing vertices.
mapToPixel Transforms the geometry from map units to pixels in place.
mergeLines Merges any connected lines in a LineString/MultiLineString geometry and converts them to single line strings.
minimalEnclosingCircle Returns the minimal enclosing circle for the geometry.
moveVertex Moves the vertex at the given position number and item (first number is index 0) to the given coordinates.
nearestPoint Returns the nearest point on this geometry to another geometry.
offsetCurve Returns an offset line at a given distance and side from an input line.
orientedMinimumBoundingBox Returns the oriented minimum bounding box for the geometry, which is the smallest (by area) rotated rectangle which fully encompasses the geometry.
orthogonalize Attempts to orthogonalize a line or polygon geometry by shifting vertices to make the geometries angles either right angles or flat lines.
overlaps Test for if geometry overlaps another (uses GEOS)
pointOnSurface Returns a point guaranteed to lie on the surface of a geometry.
poleOfInaccessibility Calculates the approximate pole of inaccessibility for a surface, which is the most distant internal point from the boundary of the surface.
polygonize Creates a GeometryCollection geometry containing possible polygons formed from the constituent linework of a set of geometries.
removeDuplicateNodes Removes duplicate nodes from the geometry, wherever removing the nodes does not result in a degenerate geometry.
removeInteriorRings Removes the interior rings from a (multi)polygon geometry.
requiresConversionToStraightSegments Returns true if the geometry is a curved geometry type which requires conversion to display as straight line segments.
reshapeGeometry Replaces a part of this geometry with another line
rotate Rotate this geometry around the Z axis
set Sets the underlying geometry store.
shortestLine Returns the shortest line joining this geometry to another geometry.
simplify Returns a simplified version of this geometry using a specified tolerance value
singleSidedBuffer Returns a single sided buffer for a (multi)line geometry.
smooth Smooths a geometry by rounding off corners using the Chaikin algorithm.
snappedToGrid Returns a new geometry with all points or vertices snapped to the closest point of the grid.
splitGeometry Splits this geometry according to a given line.
sqrDistToVertexAt Returns the squared Cartesian distance between the given point to the given vertex index (vertex at the given position number, ring and item (first number is index 0))
subdivide Subdivides the geometry.
symDifference Returns a geometry representing the points making up this geometry that do not make up other.
taperedBuffer Calculates a variable width buffer (“tapered buffer”) for a (multi)curve geometry.
touches Test for if geometry touch another (uses GEOS)
transform Transforms this geometry as described by the coordinate transform ct.
translate Translates this geometry by dx, dy, dz and dm.
type Returns type of the geometry as a QgsWkbTypes.GeometryType
unaryUnion Compute the unary union on a list of geometries.
validateGeometry Validates geometry and produces a list of geometry errors.
variableWidthBufferByM Calculates a variable width buffer for a (multi)linestring geometry, where the width at each node is taken from the linestring m values.
vertexAt Returns coordinates of a vertex.
vertexIdFromVertexNr Calculates the vertex ID from a vertex number.
vertexNrFromVertexId Returns the vertex number corresponding to a vertex id.
vertices Returns Java-style iterator for traversal of vertices of the geometry
voronoiDiagram Creates a Voronoi diagram for the nodes contained within the geometry.
within Test for if geometry is within another (uses GEOS)
wkbType Returns type of the geometry as a WKB type (point / linestring / polygon etc.)

Signals

Attributes

AddPartNotMultiGeometry
AddPartSelectedGeometryNotFound
AddRingCrossesExistingRings
AddRingNotClosed
AddRingNotInExistingFeature
AddRingNotValid
CapFlat
CapRound
CapSquare
GeometryEngineError
InvalidBaseGeometry
InvalidInputGeometryType
JoinStyleBevel
JoinStyleMiter
JoinStyleRound
LayerNotEditable
NothingHappened
SelectionIsEmpty
SelectionIsGreaterThanOne
SideLeft
SideRight
SplitCannotSplitPoint
Success
ValidatorGeos
ValidatorQgisInternal
staticMetaObject
AddPartNotMultiGeometry = 1008
AddPartSelectedGeometryNotFound = 1007
AddRingCrossesExistingRings = 1011
AddRingNotClosed = 1009
AddRingNotInExistingFeature = 1012
AddRingNotValid = 1010
class BufferSide

Bases: int

baseClass

alias of QgsGeometry

CapFlat = 2
CapRound = 1
CapSquare = 3
class EndCapStyle

Bases: int

baseClass

alias of QgsGeometry

class Error

Bases: sip.wrapper

QgsGeometry.Error(m: str) QgsGeometry.Error(m: str, p: QgsPointXY) QgsGeometry.Error(QgsGeometry.Error)

hasWhere(self) → bool
what(self) → str
where(self) → QgsPointXY
GeometryEngineError = 1005
InvalidBaseGeometry = 1001
InvalidInputGeometryType = 1002
class JoinStyle

Bases: int

baseClass

alias of QgsGeometry

JoinStyleBevel = 3
JoinStyleMiter = 2
JoinStyleRound = 1
LayerNotEditable = 1006
NothingHappened = 1000
class OperationResult

Bases: int

SelectionIsEmpty = 1003
SelectionIsGreaterThanOne = 1004
SideLeft = 0
SideRight = 1
SplitCannotSplitPoint = 1013
Success = 0
class ValidationMethod

Bases: int

ValidatorGeos = 1
ValidatorQgisInternal = 0
addPart(self, part: QgsAbstractGeometry, geomType: QgsWkbTypes.GeometryType = QgsWkbTypes.UnknownGeometry) → QgsGeometry.OperationResult

Adds a new part to this geometry.

Parameters:
  • part – part to add (ownership is transferred)
  • geomType – default geometry type to create if no existing geometry
Returns:

OperationResult a result code: success or reason of failure

addPartGeometry(self, newPart: QgsGeometry) → QgsGeometry.OperationResult

Adds a new island polygon to a multipolygon feature

Returns:OperationResult a result code: success or reason of failure

Note

available in python bindings as addPartGeometry

addPoints(self, points: object, geomType: QgsWkbTypes.GeometryType = QgsWkbTypes.UnknownGeometry) → QgsGeometry.OperationResult

Adds a new part to a the geometry.

Parameters:
  • points – points describing part to add
  • geomType – default geometry type to create if no existing geometry
Returns:

OperationResult a result code: success or reason of failure

addPointsXY(self, points: Iterable[QgsPointXY], geomType: QgsWkbTypes.GeometryType = QgsWkbTypes.UnknownGeometry) → QgsGeometry.OperationResult

Adds a new part to a the geometry.

Parameters:
  • points – points describing part to add
  • geomType – default geometry type to create if no existing geometry
Returns:

OperationResult a result code: success or reason of failure

addRing(self, ring: Iterable[QgsPointXY]) → QgsGeometry.OperationResult

Adds a new ring to this geometry. This makes only sense for polygon and multipolygons.

Parameters:ring – The ring to be added
Returns:OperationResult a result code: success or reason of failure

addRing(self, ring: QgsCurve) -> QgsGeometry.OperationResult Adds a new ring to this geometry. This makes only sense for polygon and multipolygons.

Parameters:ring – The ring to be added
Returns:OperationResult a result code: success or reason of failure
adjacentVertices(self, atVertex: int) → Tuple[int, int]

Returns the indexes of the vertices before and after the given vertex index.

This function takes into account the following factors:

1. If the given vertex index is at the end of a linestring, the adjacent index will be -1 (for “no adjacent vertex”) 2. If the given vertex index is at the end of a linear ring (such as in a polygon), the adjacent index will take into account the first vertex is equal to the last vertex (and will skip equal vertex positions).

angleAtVertex(self, vertex: int) → float

Returns the bisector angle for this geometry at the specified vertex.

Parameters:vertex – vertex index to calculate bisector angle at
Returns:bisector angle, in radians clockwise from north

New in version 3.0.

area(self) → float

Returns the area of the geometry using GEOS

New in version 1.5.

asGeometryCollection(self) → List[QgsGeometry]

Returns contents of the geometry as a list of geometries

New in version 1.1.

asJson(self, precision: int = 17) → str

Exports the geometry to a GeoJSON string.

asMultiPoint(self) → object

Returns contents of the geometry as a multi point if wkbType is WKBMultiPoint, otherwise an empty list

asMultiPolygon(self) → object

Returns contents of the geometry as a multi polygon if wkbType is WKBMultiPolygon, otherwise an empty list

asMultiPolyline(self) → object

Returns contents of the geometry as a multi linestring if wkbType is WKBMultiLineString, otherwise an empty list

asPoint(self) → QgsPointXY

Returns contents of the geometry as a point if wkbType is WKBPoint, otherwise returns [0,0]

asPolygon(self) → object

Returns contents of the geometry as a polygon if wkbType is WKBPolygon, otherwise an empty list

asPolyline(self) → List[QgsPointXY]

Returns contents of the geometry as a polyline if wkbType is WKBLineString, otherwise an empty list

asQPointF(self) → QPointF

Returns contents of the geometry as a QPointF if wkbType is WKBPoint, otherwise returns a null QPointF.

New in version 2.7.

asQPolygonF(self) → QPolygonF

Returns contents of the geometry as a QPolygonF. If geometry is a linestring, then the result will be an open QPolygonF. If the geometry is a polygon, then the result will be a closed QPolygonF of the geometry’s exterior ring.

New in version 2.7.

asWkb(self) → QByteArray

Export the geometry to WKB

New in version 3.0.

asWkt(self, precision: int = 17) → str

Exports the geometry to WKT

Returns:true in case of success and false else

Note

precision parameter added in QGIS 2.4

avoidIntersections(self, avoidIntersectionsLayers: Iterable[QgsVectorLayer]) → int

Modifies geometry to avoid intersections with the layers specified in project properties

Returns:

0 in case of success, 1 if geometry is not of polygon type, 2 if avoid intersection would change the geometry type, 3 other error during intersection removal

Parameters:
  • avoidIntersectionsLayers – list of layers to check for intersections
  • ignoreFeatures – possibility to give a list of features where intersections should be ignored (not available in Python bindings)

New in version 1.5.

boundingBox(self) → QgsRectangle

Returns the bounding box of the geometry.

boundingBoxIntersects(self, rectangle: QgsRectangle) → bool

Returns true if the bounding box of this geometry intersects with a rectangle. Since this test only considers the bounding box of the geometry, is is very fast to calculate and handles invalid geometries.

See also

intersects()

New in version 3.0.

boundingBoxIntersects(self, geometry: QgsGeometry) -> bool Returns true if the bounding box of this geometry intersects with the bounding box of another geometry. Since this test only considers the bounding box of the geometries, is is very fast to calculate and handles invalid geometries.

See also

intersects()

New in version 3.0.

buffer(self, distance: float, segments: int) → QgsGeometry

Returns a buffer region around this geometry having the given width and with a specified number of segments used to approximate curves

See also

taperedBuffer()

buffer(self, distance: float, segments: int, endCapStyle: QgsGeometry.EndCapStyle, joinStyle: QgsGeometry.JoinStyle, miterLimit: float) -> QgsGeometry Returns a buffer region around the geometry, with additional style options.

Parameters:
  • distance – buffer distance
  • segments – for round joins, number of segments to approximate quarter-circle
  • endCapStyle – end cap style
  • joinStyle – join style for corners in geometry
  • miterLimit – limit on the miter ratio used for very sharp corners (JoinStyleMiter only)

See also

taperedBuffer()

New in version 2.4.

centroid(self) → QgsGeometry

Returns the center of mass of a geometry.

If the input is a NULL geometry, the output will also be a NULL geometry.

If an error was encountered while creating the result, more information can be retrieved by calling error() on the returned geometry.

Note

for line based geometries, the center point of the line is returned, and for point based geometries, the point itself is returned

See also

pointOnSurface()

clipped(self, rectangle: QgsRectangle) → QgsGeometry

Clips the geometry using the specified rectangle.

Performs a fast, non-robust intersection between the geometry and a rectangle. The returned geometry may be invalid.

New in version 3.0.

closestSegmentWithContext(self, point: QgsPointXY, epsilon: float = DEFAULT_SEGMENT_EPSILON) → Tuple[float, QgsPointXY, int, int]

Searches for the closest segment of geometry to the given point

Parameters:
  • point – Specifies the point for search
  • minDistPoint – Receives the nearest point on the segment
  • afterVertex – Receives index of the vertex after the closest segment. The vertex before the closest segment is always afterVertex - 1
  • leftOf – Out: Returns if the point lies on the left of left side of the geometry ( < 0 means left, > 0 means right, 0 indicates that the test was unsuccessful, e.g. for a point exactly on the line)
  • epsilon – epsilon for segment snapping
Returns:

The squared Cartesian distance is also returned in sqrDist, negative number on error

closestVertex(self, point: QgsPointXY) → Tuple[QgsPointXY, int, int, int, float]
closestVertexWithContext(self, point: QgsPointXY) → Tuple[float, int]

Searches for the closest vertex in this geometry to the given point.

Parameters:
  • point – Specifiest the point for search
  • atVertex – Receives index of the closest vertex
Returns:

The squared Cartesian distance is also returned in sqrDist, negative number on error

collectGeometry(geometries: Iterable[QgsGeometry]) → QgsGeometry

Creates a new multipart geometry from a list of QgsGeometry objects

combine(self, geometry: QgsGeometry) → QgsGeometry

Returns a geometry representing all the points in this geometry and other (a union geometry operation).

If the input is a NULL geometry, the output will also be a NULL geometry.

If an error was encountered while creating the result, more information can be retrieved by calling error() on the returned geometry.

Note

this operation is not called union since its a reserved word in C++.

compare(obj1: object, obj2: object, epsilon: float = 4*DBL_EPSILON) → bool

Compares two geometry objects for equality within a specified tolerance. The objects can be of type QgsPolylineXY, QgsPolygonXYor QgsMultiPolygon. The 2 types should match.

Parameters:
  • p1 – first geometry object
  • p2 – second geometry object
  • epsilon – maximum difference for coordinates between the objects
Returns:

true if objects are - polylines and have the same number of points and all points are equal within the specified tolerance - polygons and have the same number of points and all points are equal within the specified tolerance - multipolygons and have the same number of polygons, the polygons have the same number of rings, and each ring has the same number of points and all points are equal within the specified tolerance

New in version 2.9.

constGet(self) → QgsAbstractGeometry

Returns a non-modifiable (const) reference to the underlying abstract geometry primitive.

This is much faster then calling the non-const get() method.

Note

In QGIS 2.x this method was named geometry().

See also

set()

See also

get()

New in version 3.0.

contains(self, p: QgsPointXY) → bool

Tests for containment of a point (uses GEOS)

contains(self, geometry: QgsGeometry) -> bool Tests for if geometry is contained in another (uses GEOS)

New in version 1.5.

convertGeometryCollectionToSubclass(self, geomType: QgsWkbTypes.GeometryType) → bool

Converts geometry collection to a the desired geometry type subclass (multi-point, multi-linestring or multi-polygon). Child geometries of different type are filtered out. Does nothing the geometry is not a geometry collection. May leave the geometry empty if none of the child geometries match the desired type.

Returns:true in case of success and false else

New in version 3.2.

convertPointList(input: Iterable[QgsPointXY], output: object)

Upgrades a point list from QgsPointXY to QgsPoint

Parameters:
  • input – list of QgsPointXY objects to be upgraded
  • output – destination for list of points converted to QgsPoint

convertPointList(input: object, output: Iterable[QgsPointXY]) Downgrades a point list from QgsPoint to QgsPointXY

Parameters:
  • input – list of QgsPoint objects to be downgraded
  • output – destination for list of points converted to QgsPointXY
convertToMultiType(self) → bool

Converts single type geometry into multitype geometry e.g. a polygon into a multipolygon geometry with one polygon If it is already a multipart geometry, it will return true and not change the geometry.

Returns:true in case of success and false else
convertToSingleType(self) → bool

Converts multi type geometry into single type geometry e.g. a multipolygon into a polygon geometry. Only the first part of the multi geometry will be retained. If it is already a single part geometry, it will return true and not change the geometry.

Returns:true in case of success and false else
convertToStraightSegment(self, tolerance: float = M_PI/180, toleranceType: QgsAbstractGeometry.SegmentationToleranceType = QgsAbstractGeometry.MaximumAngle)

Converts the geometry to straight line segments, if it is a curved geometry type.

Parameters:
  • tolerance – segmentation tolerance
  • toleranceType – maximum segmentation angle or maximum difference between approximation and curve

New in version 2.10.

convertToType(self, destType: QgsWkbTypes.GeometryType, destMultipart: bool = False) → QgsGeometry

Try to convert the geometry to the requested type

Parameters:
  • destType – the geometry type to be converted to
  • destMultipart – determines if the output geometry will be multipart or not
Returns:

the converted geometry or None if the conversion fails.

New in version 2.2.

convexHull(self) → QgsGeometry

Returns the smallest convex polygon that contains all the points in the geometry.

If the input is a NULL geometry, the output will also be a NULL geometry.

If an error was encountered while creating the result, more information can be retrieved by calling error() on the returned geometry.

createGeometryEngine(geometry: QgsAbstractGeometry) → QgsGeometryEngine

Creates and returns a new geometry engine

createPolygonFromQPolygonF(polygon: QPolygonF) → object

Creates a QgsPolygonXYfrom a QPolygonF.

Parameters:polygon – source polygon
Returns:QgsPolygon
createPolylineFromQPolygonF(polygon: QPolygonF) → List[QgsPointXY]

Creates a QgsPolylineXY from a QPolygonF.

Parameters:polygon – source polygon
Returns:QgsPolylineXY
createWedgeBuffer(center: QgsPoint, azimuth: float, angularWidth: float, outerRadius: float, innerRadius: float = 0) → QgsGeometry

Creates a wedge shaped buffer from a center point.

The azimuth gives the angle (in degrees) for the middle of the wedge to point. The buffer width (in degrees) is specified by the angularWidth parameter. Note that the wedge will extend to half of the angularWidth either side of the azimuth direction.

The outer radius of the buffer is specified via outerRadius, and optionally an innerRadius can also be specified.

The returned geometry will be a CurvePolygon geometry containing circular strings. It may need to be segmentized to convert to a standard Polygon geometry.

New in version 3.2.

crosses(self, geometry: QgsGeometry) → bool

Test for if geometry crosses another (uses GEOS)

New in version 1.5.

delaunayTriangulation(self, tolerance: float = 0, edgesOnly: bool = False) → QgsGeometry

Returns the Delaunay triangulation for the vertices of the geometry. The tolerance parameter specifies an optional snapping tolerance which can be used to improve the robustness of the triangulation. If edgesOnly is true than line string boundary geometries will be returned instead of polygons. An empty geometry will be returned if the diagram could not be calculated.

New in version 3.0.

deletePart(self, partNum: int) → bool

Deletes part identified by the part number

Returns:true on success

New in version 1.2.

deleteRing(self, ringNum: int, partNum: int = 0) → bool

Deletes a ring in polygon or multipolygon. Ring 0 is outer ring and can’t be deleted.

Returns:true on success

New in version 1.2.

deleteVertex(self, atVertex: int) → bool

Deletes the vertex at the given position number and item (first number is index 0)

Returns:false if atVertex does not correspond to a valid vertex on this geometry (including if this geometry is a Point), or if the number of remaining vertices in the linestring would be less than two. It is up to the caller to distinguish between these error conditions. (Or maybe we add another method to this object to help make the distinction?)
densifyByCount(self, extraNodesPerSegment: int) → QgsGeometry

Returns a copy of the geometry which has been densified by adding the specified number of extra nodes within each segment of the geometry. If the geometry has z or m values present then these will be linearly interpolated at the added nodes. Curved geometry types are automatically segmentized by this routine.

New in version 3.0.

densifyByDistance(self, distance: float) → QgsGeometry

Densifies the geometry by adding regularly placed extra nodes inside each segment so that the maximum distance between any two nodes does not exceed the specified distance. E.g. specifying a distance 3 would cause the segment [0 0] -> [10 0] to be converted to [0 0] -> [2.5 0] -> [5 0] -> [7.5 0] -> [10 0], since 3 extra nodes are required on the segment and spacing these at 2.5 increments allows them to be evenly spaced over the segment. If the geometry has z or m values present then these will be linearly interpolated at the added nodes. Curved geometry types are automatically segmentized by this routine.

See also

densifyByCount()

New in version 3.0.

difference(self, geometry: QgsGeometry) → QgsGeometry

Returns a geometry representing the points making up this geometry that do not make up other.

If the input is a NULL geometry, the output will also be a NULL geometry.

If an error was encountered while creating the result, more information can be retrieved by calling error() on the returned geometry.

disjoint(self, geometry: QgsGeometry) → bool

Tests for if geometry is disjoint of another (uses GEOS)

New in version 1.5.

distance(self, geom: QgsGeometry) → float

Returns the minimum distance between this geometry and another geometry, using GEOS. Will return a negative value if a geometry is missing.

Parameters:geom – geometry to find minimum distance to
distanceToVertex(self, vertex: int) → float

Returns the distance along this geometry from its first vertex to the specified vertex.

Parameters:vertex – vertex index to calculate distance to
Returns:distance to vertex (following geometry), or -1 for invalid vertex numbers

New in version 2.16.

draw(self, p: QPainter)

Draws the geometry onto a QPainter

Parameters:p – destination QPainter

New in version 2.10.

equals(self, geometry: QgsGeometry) → bool

Test if this geometry is exactly equal to another geometry.

This is a strict equality check, where the underlying geometries must have exactly the same type, component vertices and vertex order.

Calling this method is dramatically faster than the topological equality test performed by isGeosEqual().

Note

Comparing two null geometries will return false.

See also

isGeosEqual()

New in version 1.5.

extendLine(self, startDistance: float, endDistance: float) → QgsGeometry

Extends a (multi)line geometry by extrapolating out the start or end of the line by a specified distance. Lines are extended using the bearing of the first or last segment in the line.

New in version 3.0.

extrude(self, x: float, y: float) → QgsGeometry

Returns an extruded version of this geometry.

fromMultiPointXY(multipoint: object) → QgsGeometry

Creates a new geometry from a QgsMultiPointXY object

fromMultiPolygonXY(multipoly: object) → QgsGeometry

Creates a new geometry from a QgsMultiPolygon

fromMultiPolylineXY(multiline: object) → QgsGeometry

Creates a new geometry from a QgsMultiPolylineXY object

fromPointXY(point: QgsPointXY) → QgsGeometry

Creates a new geometry from a QgsPointXY object

fromPolygonXY(polygon: object) → QgsGeometry

Creates a new geometry from a QgsPolygon

fromPolyline(polyline: Iterable[QgsPoint]) → QgsGeometry

Creates a new LineString geometry from a list of QgsPoint points.

This method will respect any Z or M dimensions present in the input points. E.g. if input points are PointZ type, the resultant linestring will be a LineStringZ type.

New in version 3.0.

fromPolylineXY(polyline: Iterable[QgsPointXY]) → QgsGeometry

Creates a new LineString geometry from a list of QgsPointXY points.

Using fromPolyline() is preferred, as fromPolyline() is more efficient and will respect any Z or M dimensions present in the input points.

Note

In QGIS 2.x this method was available as fromPolyline().

See also

fromPolyline()

New in version 3.0.

fromQPointF(point: Union[QPointF, QPoint]) → QgsGeometry

Construct geometry from a QPointF

Parameters:point – source QPointF

New in version 2.7.

fromQPolygonF(polygon: QPolygonF) → QgsGeometry

Construct geometry from a QPolygonF. If the polygon is closed than the resultant geometry will be a polygon, if it is open than the geometry will be a polyline.

Parameters:polygon – source QPolygonF

New in version 2.7.

fromRect(rect: QgsRectangle) → QgsGeometry

Creates a new geometry from a QgsRectangle

fromWkb(self, wkb: Union[QByteArray, bytes, bytearray])

Set the geometry, feeding in the buffer containing OGC Well-Known Binary

New in version 3.0.

fromWkt(wkt: str) → QgsGeometry

Creates a new geometry from a WKT string

get(self) → QgsAbstractGeometry

Returns a modifiable (non-const) reference to the underlying abstract geometry primitive.

This method can be slow to call, as it may trigger a detachment of the geometry and a deep copy. Where possible, use constGet() instead.

Note

In QGIS 2.x this method was named geometry().

See also

constGet()

See also

set()

New in version 3.0.

hausdorffDistance(self, geom: QgsGeometry) → float

Returns the Hausdorff distance between this geometry and geom. This is basically a measure of how similar or dissimilar 2 geometries are.

This algorithm is an approximation to the standard Hausdorff distance. This approximation is exact or close enough for a large subset of useful cases. Examples of these are:

  • computing distance between Linestrings that are roughly parallel to each other,

and roughly equal in length. This occurs in matching linear networks. - Testing similarity of geometries.

If the default approximate provided by this method is insufficient, use hausdorffDistanceDensify() instead.

In case of error -1 will be returned.

New in version 3.0.

hausdorffDistanceDensify(self, geom: QgsGeometry, densifyFraction: float) → float

Returns the Hausdorff distance between this geometry and geom. This is basically a measure of how similar or dissimilar 2 geometries are.

This function accepts a densifyFraction argument. The function performs a segment densification before computing the discrete Hausdorff distance. The densifyFraction parameter sets the fraction by which to densify each segment. Each segment will be split into a number of equal-length subsegments, whose fraction of the total length is closest to the given fraction.

This method can be used when the default approximation provided by hausdorffDistance() is not sufficient. Decreasing the densifyFraction parameter will make the distance returned approach the true Hausdorff distance for the geometries.

In case of error -1 will be returned.

New in version 3.0.

insertVertex(self, x: float, y: float, beforeVertex: int) → bool

Insert a new vertex before the given vertex index, ring and item (first number is index 0) If the requested vertex number (beforeVertex.back()) is greater than the last actual vertex on the requested ring and item, it is assumed that the vertex is to be appended instead of inserted. Returns false if atVertex does not correspond to a valid vertex on this geometry (including if this geometry is a Point). It is up to the caller to distinguish between these error conditions. (Or maybe we add another method to this object to help make the distinction?)

insertVertex(self, point: QgsPoint, beforeVertex: int) -> bool Insert a new vertex before the given vertex index, ring and item (first number is index 0) If the requested vertex number (beforeVertex.back()) is greater than the last actual vertex on the requested ring and item, it is assumed that the vertex is to be appended instead of inserted. Returns false if atVertex does not correspond to a valid vertex on this geometry (including if this geometry is a Point). It is up to the caller to distinguish between these error conditions. (Or maybe we add another method to this object to help make the distinction?)

interpolate(self, distance: float) → QgsGeometry

Returns an interpolated point on the geometry at the specified distance.

If the original geometry is a polygon type, the boundary of the polygon will be used during interpolation. If the original geometry is a point type, a null geometry will be returned.

If z or m values are present, the output z and m will be interpolated using the existing vertices’ z or m values.

If the input is a NULL geometry, the output will also be a NULL geometry.

New in version 2.0.

interpolateAngle(self, distance: float) → float

Returns the angle parallel to the linestring or polygon boundary at the specified distance along the geometry. Angles are in radians, clockwise from north. If the distance coincides precisely at a node then the average angle from the segment either side of the node is returned.

Parameters:distance – distance along geometry

See also

angleAtVertex()

New in version 3.0.

intersection(self, geometry: QgsGeometry) → QgsGeometry

Returns a geometry representing the points shared by this geometry and other.

If the input is a NULL geometry, the output will also be a NULL geometry.

If an error was encountered while creating the result, more information can be retrieved by calling error() on the returned geometry.

intersects(self, rectangle: QgsRectangle) → bool

Returns true if this geometry exactly intersects with a rectangle. This test is exact and can be slow for complex geometries.

The GEOS library is used to perform the intersection test. Geometries which are not valid may return incorrect results.

intersects(self, geometry: QgsGeometry) -> bool Returns true if this geometry exactly intersects with another geometry. This test is exact and can be slow for complex geometries.

The GEOS library is used to perform the intersection test. Geometries which are not valid may return incorrect results.

isEmpty(self) → bool

Returns true if the geometry is empty (eg a linestring with no vertices, or a collection with no geometries). A null geometry will always return true for isEmpty().

See also

isNull()

isGeosEqual(self, QgsGeometry) → bool

Compares the geometry with another geometry using GEOS.

This method performs a slow, topological check, where geometries are considered equal if all of the their component edges overlap. E.g. lines with the same vertex locations but opposite direction will be considered equal by this method.

Consider using the much faster, stricter equality test performed by equals() instead.

Note

Comparing two null geometries will return false.

See also

equals()

New in version 1.5.

isGeosValid(self) → bool

Checks validity of the geometry using GEOS

New in version 1.5.

isMultipart(self) → bool

Returns true if WKB of the geometry is of WKBMulti* type

isNull(self) → bool

Returns true if the geometry is null (ie, contains no underlying geometry accessible via geometry() ).

See also

get()

See also

isEmpty()

New in version 2.10.

isSimple(self) → bool

Determines whether the geometry is simple (according to OGC definition), i.e. it has no anomalous geometric points, such as self-intersection or self-tangency. Uses GEOS library for the test.

Note

This is useful mainly for linestrings and linear rings. Polygons are simple by definition, for checking anomalies in polygon geometries one can use isGeosValid().

New in version 3.0.

lastError(self) → str

Returns an error string referring to the last error encountered either when this geometry was created or when an operation was performed on the geometry.

New in version 3.0.

length(self) → float

Returns the length of geometry using GEOS

New in version 1.5.

lineLocatePoint(self, point: QgsGeometry) → float

Returns a distance representing the location along this linestring of the closest point on this linestring geometry to the specified point. Ie, the returned value indicates how far along this linestring you need to traverse to get to the closest location where this linestring comes to the specified point.

Parameters:point – point to seek proximity to
Returns:distance along line, or -1 on error

Note

only valid for linestring geometries

See also

interpolate()

New in version 3.0.

makeDifference(self, other: QgsGeometry) → QgsGeometry

Returns the geometry formed by modifying this geometry such that it does not intersect the other geometry.

Parameters:other – geometry that should not be intersect
Returns:difference geometry, or empty geometry if difference could not be calculated

New in version 3.0.

makeValid(self) → QgsGeometry

Attempts to make an invalid geometry valid without losing vertices.

Already-valid geometries are returned without further intervention. In case of full or partial dimensional collapses, the output geometry may be a collection of lower-to-equal dimension geometries or a geometry of lower dimension. Single polygons may become multi-geometries in case of self-intersections. It preserves Z values, but M values will be dropped.

If an error was encountered during the process, more information can be retrieved by calling error() on the returned geometry.

Returns:new valid QgsGeometry or null geometry on error

Note

Ported from PostGIS ST_MakeValid() and it should return equivalent results.

New in version 3.0.

mapToPixel(self, mtp: QgsMapToPixel)

Transforms the geometry from map units to pixels in place.

Parameters:mtp – map to pixel transform

New in version 2.10.

mergeLines(self) → QgsGeometry

Merges any connected lines in a LineString/MultiLineString geometry and converts them to single line strings.

Returns:a LineString or MultiLineString geometry, with any connected lines joined. An empty geometry will be returned if the input geometry was not a MultiLineString geometry.

New in version 3.0.

minimalEnclosingCircle(self, segments: int = 36) → Tuple[QgsGeometry, QgsPointXY, float]

Returns the minimal enclosing circle for the geometry.

Parameters:
  • center – Center of the minimal enclosing circle returneds
  • radius – Radius of the minimal enclosing circle returned
  • segments – Number of segments used to segment geometry. QgsEllipse.toPolygon()

New in version 3.0.

moveVertex(self, x: float, y: float, atVertex: int) → bool

Moves the vertex at the given position number and item (first number is index 0) to the given coordinates. Returns false if atVertex does not correspond to a valid vertex on this geometry

moveVertex(self, p: QgsPoint, atVertex: int) -> bool Moves the vertex at the given position number and item (first number is index 0) to the given coordinates. Returns false if atVertex does not correspond to a valid vertex on this geometry

nearestPoint(self, other: QgsGeometry) → QgsGeometry

Returns the nearest point on this geometry to another geometry.

See also

shortestLine()

New in version 2.14.

offsetCurve(self, distance: float, segments: int, joinStyle: QgsGeometry.JoinStyle, miterLimit: float) → QgsGeometry

Returns an offset line at a given distance and side from an input line.

Parameters:
  • distance – buffer distance
  • segments – for round joins, number of segments to approximate quarter-circle
  • joinStyle – join style for corners in geometry
  • miterLimit – limit on the miter ratio used for very sharp corners (JoinStyleMiter only)

New in version 2.4.

orientedMinimumBoundingBox(self) → Tuple[QgsGeometry, float, float, float, float]

Returns the oriented minimum bounding box for the geometry, which is the smallest (by area) rotated rectangle which fully encompasses the geometry. The area, angle (clockwise in degrees from North), width and height of the rotated bounding box will also be returned.

See also

boundingBox()

New in version 3.0.

orthogonalize(self, tolerance: float = 1e-08, maxIterations: int = 1000, angleThreshold: float = 15) → QgsGeometry

Attempts to orthogonalize a line or polygon geometry by shifting vertices to make the geometries angles either right angles or flat lines. This is an iterative algorithm which will loop until either the vertices are within a specified tolerance of right angles or a set number of maximum iterations is reached. The angle threshold parameter specifies how close to a right angle or straight line an angle must be before it is attempted to be straightened.

New in version 3.0.

overlaps(self, geometry: QgsGeometry) → bool

Test for if geometry overlaps another (uses GEOS)

New in version 1.5.

pointOnSurface(self) → QgsGeometry

Returns a point guaranteed to lie on the surface of a geometry. While the centroid() of a geometry may be located outside of the geometry itself (e.g., for concave shapes), the point on surface will always be inside the geometry.

If the input is a NULL geometry, the output will also be a NULL geometry.

If an error was encountered while creating the result, more information can be retrieved by calling error() on the returned geometry.

See also

centroid()

poleOfInaccessibility(self, precision: float) → Tuple[QgsGeometry, float]

Calculates the approximate pole of inaccessibility for a surface, which is the most distant internal point from the boundary of the surface. This function uses the ‘polylabel’ algorithm (Vladimir Agafonkin, 2016), which is an iterative approach guaranteed to find the true pole of inaccessibility within a specified tolerance. More precise tolerances require more iterations and will take longer to calculate. Optionally, the distance to the polygon boundary from the pole can be stored.

See also

centroid()

See also

pointOnSurface()

New in version 3.0.

polygonize(geometries: Iterable[QgsGeometry]) → QgsGeometry

Creates a GeometryCollection geometry containing possible polygons formed from the constituent linework of a set of geometries. The input geometries must be fully noded (i.e. nodes exist at every common intersection of the geometries). The easiest way to ensure this is to first call unaryUnion() on the set of input geometries and then pass the result to polygonize(). An empty geometry will be returned in the case of errors.

New in version 3.0.

removeDuplicateNodes(self, epsilon: float = 4*DBL_EPSILON, useZValues: bool = False) → bool

Removes duplicate nodes from the geometry, wherever removing the nodes does not result in a degenerate geometry.

The epsilon parameter specifies the tolerance for coordinates when determining that vertices are identical.

By default, z values are not considered when detecting duplicate nodes. E.g. two nodes with the same x and y coordinate but different z values will still be considered duplicate and one will be removed. If useZValues is true, then the z values are also tested and nodes with the same x and y but different z will be maintained.

Note that duplicate nodes are not tested between different parts of a multipart geometry. E.g. a multipoint geometry with overlapping points will not be changed by this method.

The function will return true if nodes were removed, or false if no duplicate nodes were found.

New in version 3.0.

removeInteriorRings(self, minimumAllowedArea: float = -1) → QgsGeometry

Removes the interior rings from a (multi)polygon geometry. If the minimumAllowedArea parameter is specified then only rings smaller than this minimum area will be removed.

New in version 3.0.

requiresConversionToStraightSegments(self) → bool

Returns true if the geometry is a curved geometry type which requires conversion to display as straight line segments.

New in version 2.10.

reshapeGeometry(self, reshapeLineString: QgsLineString) → QgsGeometry.OperationResult

Replaces a part of this geometry with another line

Returns:OperationResult a result code: success or reason of failure
rotate(self, rotation: float, center: QgsPointXY) → QgsGeometry.OperationResult

Rotate this geometry around the Z axis

Parameters:
  • rotation – clockwise rotation in degrees
  • center – rotation center
Returns:

OperationResult a result code: success or reason of failure

set(self, geometry: QgsAbstractGeometry)

Sets the underlying geometry store. Ownership of geometry is transferred.

Note

In QGIS 2.x this method was named setGeometry().

See also

get()

See also

constGet()

New in version 3.0.

shortestLine(self, other: QgsGeometry) → QgsGeometry

Returns the shortest line joining this geometry to another geometry.

See also

nearestPoint()

New in version 2.14.

simplify(self, tolerance: float) → QgsGeometry

Returns a simplified version of this geometry using a specified tolerance value

singleSidedBuffer(self, distance: float, segments: int, side: QgsGeometry.BufferSide, joinStyle: QgsGeometry.JoinStyle = QgsGeometry.JoinStyleRound, miterLimit: float = 2) → QgsGeometry

Returns a single sided buffer for a (multi)line geometry. The buffer is only applied to one side of the line.

Parameters:
  • distance – buffer distance
  • segments – for round joins, number of segments to approximate quarter-circle
  • side – side of geometry to buffer
  • joinStyle – join style for corners
  • miterLimit – limit on the miter ratio used for very sharp corners
Returns:

buffered geometry, or an empty geometry if buffer could not be calculated

See also

buffer()

See also

taperedBuffer()

New in version 3.0.

smooth(self, iterations: int = 1, offset: float = 0.25, minimumDistance: float = -1, maxAngle: float = 180) → QgsGeometry

Smooths a geometry by rounding off corners using the Chaikin algorithm. This operation roughly doubles the number of vertices in a geometry.

If input geometries contain Z or M values, these will also be smoothed and the output geometry will retain the same dimensionality as the input geometry.

Parameters:
  • iterations – number of smoothing iterations to run. More iterations results in a smoother geometry
  • offset – fraction of line to create new vertices along, between 0 and 1.0, e.g., the default value of 0.25 will create new vertices 25% and 75% along each line segment of the geometry for each iteration. Smaller values result in “tighter” smoothing.
  • minimumDistance – minimum segment length to apply smoothing to
  • maxAngle – maximum angle at node (0-180) at which smoothing will be applied

New in version 2.9.

snappedToGrid(self, hSpacing: float, vSpacing: float, dSpacing: float = 0, mSpacing: float = 0) → QgsGeometry

Returns a new geometry with all points or vertices snapped to the closest point of the grid.

If the gridified geometry could not be calculated (or was totally collapsed) an empty geometry will be returned. Note that snapping to grid may generate an invalid geometry in some corner cases. It can also be thought as rounding the edges and it may be useful for removing errors.

Parameters:
  • hSpacing – Horizontal spacing of the grid (x axis). 0 to disable.
  • vSpacing – Vertical spacing of the grid (y axis). 0 to disable.
  • dSpacing – Depth spacing of the grid (z axis). 0 (default) to disable.
  • mSpacing – Custom dimension spacing of the grid (m axis). 0 (default) to disable.

New in version 3.0.

splitGeometry(self, splitLine: Iterable[QgsPointXY], topological: bool) → Tuple[QgsGeometry.OperationResult, List[QgsGeometry], List[QgsPointXY]]

Splits this geometry according to a given line.

Parameters:splitLine – the line that splits the geometry

param[out] newGeometries list of new geometries that have been created with the split :param topological: true if topological editing is enabled param[out] topologyTestPoints points that need to be tested for topological completeness in the dataset

Returns:OperationResult a result code: success or reason of failure
sqrDistToVertexAt(self, point: QgsPointXY, atVertex: int) → float

Returns the squared Cartesian distance between the given point to the given vertex index (vertex at the given position number, ring and item (first number is index 0))

staticMetaObject = <PyQt5.QtCore.QMetaObject object>
subdivide(self, maxNodes: int = 256) → QgsGeometry

Subdivides the geometry. The returned geometry will be a collection containing subdivided parts from the original geometry, where no part has more then the specified maximum number of nodes (maxNodes).

This is useful for dividing a complex geometry into less complex parts, which are better able to be spatially indexed and faster to perform further operations such as intersects on. The returned geometry parts may not be valid and may contain self-intersections.

The minimum allowed value for maxNodes is 8.

Curved geometries will be segmentized before subdivision.

If the input is a NULL geometry, the output will also be a NULL geometry.

If an error was encountered while creating the result, more information can be retrieved by calling error() on the returned geometry.

New in version 3.0.

symDifference(self, geometry: QgsGeometry) → QgsGeometry

Returns a geometry representing the points making up this geometry that do not make up other.

If the input is a NULL geometry, the output will also be a NULL geometry.

If an error was encountered while creating the result, more information can be retrieved by calling error() on the returned geometry.

taperedBuffer(self, startWidth: float, endWidth: float, segments: int) → QgsGeometry

Calculates a variable width buffer (“tapered buffer”) for a (multi)curve geometry.

The buffer begins at a width of startWidth at the start of each curve, and ends at a width of endWidth. Note that unlike buffer() methods, startWidth and endWidth are the diameter of the buffer at these points, not the radius.

The segments argument specifies the number of segments to approximate quarter-circle curves in the buffer.

Non (multi)curve input geometries will return a null output geometry.

See also

buffer()

New in version 3.2.

touches(self, geometry: QgsGeometry) → bool

Test for if geometry touch another (uses GEOS)

New in version 1.5.

transform(self, ct: QgsCoordinateTransform, direction: QgsCoordinateTransform.TransformDirection = QgsCoordinateTransform.ForwardTransform, transformZ: bool = False) → QgsGeometry.OperationResult

Transforms this geometry as described by the coordinate transform ct.

The transformation defaults to a forward transform, but the direction can be swapped by setting the direction argument.

By default, z-coordinates are not transformed, even if the coordinate transform includes a vertical datum transformation. To transform z-coordinates, set transformZ to true. This requires that the z coordinates in the geometry represent height relative to the vertical datum of the source CRS (generally ellipsoidal heights) and are expressed in its vertical units (generally meters).

Returns:OperationResult a result code: success or reason of failure

transform(self, t: QTransform, zTranslate: float = 0, zScale: float = 1, mTranslate: float = 0, mScale: float = 1) -> QgsGeometry.OperationResult Transforms the x and y components of the geometry using a QTransform object t.

Optionally, the geometry’s z values can be scaled via zScale and translated via zTranslate. Similarly, m-values can be scaled via mScale and translated via mTranslate.

Returns:OperationResult a result code: success or reason of failure
translate(self, dx: float, dy: float, dz: float = 0, dm: float = 0) → QgsGeometry.OperationResult

Translates this geometry by dx, dy, dz and dm.

Returns:OperationResult a result code: success or reason of failure
type(self) → QgsWkbTypes.GeometryType

Returns type of the geometry as a QgsWkbTypes.GeometryType

See also

wkbType()

unaryUnion(geometries: Iterable[QgsGeometry]) → QgsGeometry

Compute the unary union on a list of geometries. May be faster than an iterative union on a set of geometries. The returned geometry will be fully noded, i.e. a node will be created at every common intersection of the input geometries. An empty geometry will be returned in the case of errors.

validateGeometry(self, method: QgsGeometry.ValidationMethod = QgsGeometry.ValidatorQgisInternal) → List[QgsGeometry.Error]

Validates geometry and produces a list of geometry errors. The method argument dictates which validator to utilize.

Note

Available in Python bindings since QGIS 1.6

New in version 1.5.

variableWidthBufferByM(self, segments: int) → QgsGeometry

Calculates a variable width buffer for a (multi)linestring geometry, where the width at each node is taken from the linestring m values.

The segments argument specifies the number of segments to approximate quarter-circle curves in the buffer.

Non (multi)linestring input geometries will return a null output geometry.

See also

buffer()

See also

taperedBuffer()

New in version 3.2.

vertexAt(self, atVertex: int) → QgsPoint

Returns coordinates of a vertex.

Parameters:atVertex – index of the vertex
Returns:Coordinates of the vertex or QgsPoint(0,0) on error
vertexIdFromVertexNr(self, number: int) → Tuple[bool, QgsVertexId]

Calculates the vertex ID from a vertex number.

If a matching vertex was found, it will be stored in id.

Returns true if vertex was found.

New in version 2.10.

vertexNrFromVertexId(self, id: QgsVertexId) → int

Returns the vertex number corresponding to a vertex id.

The vertex numbers start at 0, so a return value of 0 corresponds to the first vertex.

Returns -1 if a corresponding vertex could not be found.

New in version 2.10.

vertices(self) → QgsVertexIterator

Returns Java-style iterator for traversal of vertices of the geometry

New in version 3.0.

voronoiDiagram(self, extent: QgsGeometry = QgsGeometry(), tolerance: float = 0, edgesOnly: bool = False) → QgsGeometry

Creates a Voronoi diagram for the nodes contained within the geometry.

Returns the Voronoi polygons for the nodes contained within the geometry. If extent is specified then it will be used as a clipping envelope for the diagram. If no extent is set then the clipping envelope will be automatically calculated. In either case the diagram will be clipped to the larger of the provided envelope OR the envelope surrounding all input nodes. The tolerance parameter specifies an optional snapping tolerance which can be used to improve the robustness of the diagram calculation. If edgesOnly is true than line string boundary geometries will be returned instead of polygons. An empty geometry will be returned if the diagram could not be calculated.

New in version 3.0.

within(self, geometry: QgsGeometry) → bool

Test for if geometry is within another (uses GEOS)

New in version 1.5.

wkbType(self) → QgsWkbTypes.Type

Returns type of the geometry as a WKB type (point / linestring / polygon etc.)

See also

type()