Class: QgsEllipse¶

Ellipse geometry type.

An ellipse is defined by a center point with a semi-major axis, a semi-minor axis and an azimuth. The azimuth is the north angle to the first quadrant (always oriented on the semi-major axis), in degrees. By default, the semi-major axis is oriented to the east (90 degrees). The semi-minor axis is always smaller than the semi-major axis. If it is set larger, it will be swapped and the azimuth will increase by 90 degrees.

Class Hierarchy¶

Subclasses¶

QgsCircle

Circle geometry type.

class qgis.core.QgsEllipse[source]¶

Bases: object

__init__(): Constructor for QgsEllipse.

__init__(center: QgsPoint, semiMajorAxis: float, semiMinorAxis: float, azimuth: float = 90)

Constructs an ellipse by defining all the members.

Parameters:

center (QgsPoint) – The center of the ellipse.
semiMajorAxis (float) – Semi-major axis of the ellipse.
semiMinorAxis (float) – Semi-minor axis of the ellipse.
azimuth (float = 90) – Angle in degrees started from the North to the first quadrant.

__init__(a0: QgsEllipse)

Parameters:: a0 (QgsEllipse)

virtual area(self) → float[source]¶

The area of the ellipse.

Return type:: float

azimuth(self) → float[source]¶

Returns the azimuth.

See also

setAzimuth()

Return type:: float

virtual boundingBox(self) → QgsRectangle[source]¶

Returns the minimal bounding box for the ellipse.

Return type:: QgsRectangle

center(self) → QgsPoint[source]¶

Returns the center point.

See also

setCenter()

See also

rcenter()

Return type:: QgsPoint

virtual eccentricity(self) → float[source]¶

The eccentricity of the ellipse. nan is returned if the ellipse is empty.

Return type:: float

virtual foci(self) → List[QgsPoint]¶

Two foci of the ellipse. The axes are oriented by the azimuth and are on the semi-major axis.

See also

fromFoci()

See also

focusDistance()

Return type:: List[QgsPoint]
Returns:: the two foci.

virtual focusDistance(self) → float[source]¶

The distance between the center and each foci.

See also

fromFoci()

See also

foci()

Return type:: float
Returns:: The distance between the center and each foci.

static fromCenter2Points(ptc: QgsPoint, pt1: QgsPoint, pt2: QgsPoint) → QgsEllipse[source]¶

Constructs an ellipse by a central point and two other points. The center point keeps m value from ptc. Z dimension is also supported and is retrieved from the first 3D point amongst ptc, pt1 and pt2. Axes are calculated from the 2D distance between ptc and pt1 and pt2. The azimuth is the angle between ptc and pt1.

Parameters:

ptc (QgsPoint) – Center point.
pt1 (QgsPoint) – First point.
pt2 (QgsPoint) – Second point.

Return type:

QgsEllipse

static fromCenterPoint(ptc: QgsPoint, pt1: QgsPoint) → QgsEllipse[source]¶

Constructs an ellipse by a center point and a another point. The center point keeps m value from ptc. Z dimension is also supported and is retrieved from the first 3D point amongst ptc and pt1. Axes are calculated from the 2D distance between ptc and pt1. The azimuth always takes the default value.

Parameters:

ptc (QgsPoint) – Center point.
pt1 (QgsPoint) – First point.

Return type:

QgsEllipse

static fromExtent(pt1: QgsPoint, pt2: QgsPoint) → QgsEllipse[source]¶

Constructs an ellipse by an extent (aka bounding box / QgsRectangle). The center point can have m value which is the result from the midpoint operation between pt1 and pt2. Z dimension is also supported and is retrieved from the first 3D point amongst pt1 and pt2. Axes are calculated from the 2D distance between pt1 and pt2. The azimuth always takes the default value.

Parameters:

pt1 (QgsPoint) – First corner.
pt2 (QgsPoint) – Second corner.

Return type:

QgsEllipse

static fromFoci(pt1: QgsPoint, pt2: QgsPoint, pt3: QgsPoint) → QgsEllipse[source]¶

Constructs an ellipse by foci (pt1 and pt2) and a point pt3. The center point can have m value which is the result from the midpoint operation between pt1 and pt2. Z dimension is also supported and is retrieved from the first 3D point amongst pt1 and pt2. Axes are calculated from the 2D distance with the third point pt3. The azimuth is the angle between pt1 and pt2.

Parameters:

pt1 (QgsPoint) – First focus.
pt2 (QgsPoint) – Second focus.
pt3 (QgsPoint) – A point to calculate the axes.

Return type:

QgsEllipse

virtual isEmpty(self) → bool[source]¶

An ellipse is empty if axes are equal to 0

Return type:: bool

virtual orientedBoundingBox(self) → QgsPolygon | None[source]¶

Returns the oriented minimal bounding box for the ellipse.

Return type:: Optional[QgsPolygon]

virtual perimeter(self) → float[source]¶

The circumference of the ellipse using first approximation of Ramanujan.

Return type:: float

virtual points(self, segments: int = 36) → List[QgsPoint][source]¶

Returns a list of points with segmentation from segments.

Parameters:: segments (int = 36) – Number of segments used to segment geometry.
Return type:: List[QgsPoint]

virtual quadrant(self) → List[QgsPoint]¶

The four quadrants of the ellipse. They are oriented and started always from semi-major axis.

Return type:: List[QgsPoint]
Returns:: quadrants defined by four points.

semiMajorAxis(self) → float[source]¶

Returns the semi-major axis.

See also

setSemiMajorAxis()

Return type:: float

semiMinorAxis(self) → float[source]¶

Returns the semi-minor axis.

See also

setSemiMinorAxis()

Return type:: float

setAzimuth(self, azimuth: float)[source]¶

Sets the azimuth (orientation).

See also

azimuth()

Parameters:: azimuth (float)

setCenter(self, center: QgsPoint)[source]¶

Sets the center point.

See also

center()

See also

rcenter()

Parameters:: center (QgsPoint)

virtual setSemiMajorAxis(self, semiMajorAxis: float)[source]¶

Sets the semi-major axis.

See also

semiMajorAxis()

Parameters:: semiMajorAxis (float)

virtual setSemiMinorAxis(self, semiMinorAxis: float)[source]¶

Sets the semi-minor axis.

See also

semiMinorAxis()

Parameters:: semiMinorAxis (float)

virtual toLineString(self, segments: int = 36) → QgsLineString | None[source]¶

Returns a segmented linestring.

Parameters:: segments (int = 36) – Number of segments used to segment geometry.
Return type:: Optional[QgsLineString]

virtual toPolygon(self, segments: int = 36) → QgsPolygon | None[source]¶

Returns a segmented polygon.

Parameters:: segments (int = 36) – Number of segments used to segment geometry.
Return type:: Optional[QgsPolygon]

virtual toString(self, pointPrecision: int = 17, axisPrecision: int = 17, azimuthPrecision: int = 2) → str[source]¶

returns a string representation of the ellipse. Members will be truncated to the specified precision.

Parameters:

pointPrecision (int = 17)
axisPrecision (int = 17)
azimuthPrecision (int = 2)

Return type:

str