Arc2D

Class full path: NemAll_Python_Geometry.Arc2D

Representation class for 2D arc.

Arc2D could be a circular or elliptical arc. All angles are given as central angles. In case of an elliptical arc the ellipse angle and the central angle do not correspond. All start angle is normalized to the range [-PI..2PI]. The winding direction of the arc could either be in clockwise or in counterclockwise direction.

Examples:

Circle with radius of 1000 mm and center point in 0,0
>>> Arc2D(Point2D(), 1000)

Circular 180 deg arc without axis rotation
>>> Arc2D(Point2D(), 1000, 1000, 0.0, 0.0, 3.14)

Circular 180 deg arc with 90 deg axis rotation:
>>> Arc2D(Point2D(), 1000, 1000, 3.14/2, 0.0, 3.14)

The same arc could be created without axis rotation only by increasing the start and end angles 
by the axis angle like this:
>>> Arc2D(Point2D(), 1000, 1000, 0.0, 3.14/2, 3.14 + 3.14/2)

Elliptical 180 deg arc with major radius (at 0 deg) of 1000mm and minor radius (at 90 deg) of 500mm
>>> Arc2D(Point2D(), 500, 1000, 0, 0, 3.14)

Attributes

AxisAngle: Angle property writable

Get the axis angle

Returns the the angle of the major axis

Center: Point2D property writable

Get center point

CenterRel: Point2D property writable

Get center point in relative coordinate system.

CounterClockwise: bool property writable

Returns winding direction counterclockwise true/false

DeltaAngle: Angle property

Get difference between EndAngle and StartAngle

EndAngle: Angle property writable

Get end angle

EndPoint: Point2D property writable

Get the end point in world coordinate system.

EndRelPoint: Point2D property

Get the end point in relative coordinate system

MajorRadius: float property writable

Get major radius

MinorRadius: float property writable

Get minor radius

RefPoint: Point2D property writable

Get reference point

StartAngle: Angle property writable

Get start angle

StartPoint: Point2D property writable

Get the start point in world coordinate system.

StartRelPoint: Point2D property

Get the start point in relative coordinate system

Functions

Close()

Close arc

End angle will be adjusted to close arc.

EqualRef(arc)

Test for equal reference points

Parameters:

Name	Type	Description	Default
arc	Arc2D	Arc which will be compared	required

Returns:

Type	Description
bool	result as bool

GetAxisAngle()

Get the axis angle

Returns the the angle of the major axis

Returns:

Type	Description
Angle	axis angle.

GetCenter()

Get center point

Returns:

Type	Description
Point2D	center point

GetCenterRel()

Get center point in relative coordinate system.

Returns:

Type	Description
Point2D	center point

GetDeltaAngle()

Get difference between EndAngle and StartAngle

Returns:

Type	Description
Angle	delta angle

GetEndAngle()

Get end angle

Returns:

Type	Description
Angle	end angle

GetEndPoint()

Get the end point in world coordinate system.

Returns:

Type	Description
Point2D	point.

GetEndRelPoint()

Get the end point in relative coordinate system

Returns:

Type	Description
Point2D	constant point.

GetEndTangent()

Get tangent vector at the end point of Arc

Returns:

Type	Description
Vector2D	Tangent vector (unit vector)

GetMajorRadius()

Get major radius

Returns:

Type	Description
float	major radius

GetMinorRadius()

Get minor radius

Returns:

Type	Description
float	minor radius

GetPoint(angle)

Get point on Arc in world coordinate system

Calculates the point at central angle in parameter angle on the Arc

Parameters:

Name	Type	Description	Default
angle	Angle	central angle of the point	required

Returns:

Type	Description
Point2D	point on Arc

GetRefPoint()

Get reference point

Returns:

Type	Description
Point2D	reference point

GetStartAngle()

Get start angle

Returns:

Type	Description
Angle	start angle

GetStartPoint()

Get the start point in world coordinate system.

Returns:

Type	Description
Point2D	point.

GetStartRelPoint()

Get the start point in relative coordinate system

Returns:

Type	Description
Point2D	constant point.

GetStartTangent()

Get tangent vector at the start point of Arc

Returns:

Type	Description
Vector2D	Tangent vector (unit vector)

IsAngleOnArc(angle)

Checks if the given angle lies on the arc

Parameters:

Name	Type	Description	Default
angle	Angle	angle angle to test	required

Returns:

Type	Description
bool	Angle on arc true/false

IsCircle()

Test if ellipse is circle

Tests if major radius equals minor radius

Returns:

Type	Description
bool	if ellipse is circle

IsClosed()

Check if arc is closed ( Full circle/ellipse )

Returns:

Type	Description
bool	closed curve true/false

IsCounterClockwise()

Returns winding direction counterclockwise true/false

Returns:

Type	Description
bool	Is counterclockwise true/false

Reverse()

Reverse of current arc

Method reverse Arc, start with end angle and orientation.

SetAxisAngle(angle)

Set the axis angle

Set the angle of the major axis

Parameters:

Name	Type	Description	Default
angle	Angle	axis angle	required

SetCenter(center)

Set center point

Parameters:

Name	Type	Description	Default
center	Point2D	center point	required

SetCenterRel(center)

Set center point in local coordinate system

Parameters:

Name	Type	Description	Default
center	Point2D	center point	required

SetCounterClockwise(ccw)

Set the winding direction of the arc

Parameters:

Name	Type	Description	Default
ccw	bool	winding counterclockwise true/false	required

SetEndAngle(angle)

Set end angle

Set the end angle

Parameters:

Name	Type	Description	Default
angle	Angle	end angle	required

SetEndPoint(endpoint)

Set the end point in world coordinate system

Parameters:

Name	Type	Description	Default
endpoint	Point2D	constant 2D point	required

SetMajorRadius(radius)

Set major radius

Parameters:

Name	Type	Description	Default
radius	float	major radius	required

SetMinorRadius(radius)

Set minor radius

Parameters:

Name	Type	Description	Default
radius	float	minor radius	required

SetRefPoint(refPoint)

Set reference point

Parameters:

Name	Type	Description	Default
refPoint	Point2D	reference point	required

SetStartAngle(angle)

Set start angle

Set the start angle

Parameters:

Name	Type	Description	Default
angle	Angle	start angle	required

SetStartPoint(startpoint)

Set the start point in world coordinate system

Parameters:

Name	Type	Description	Default
startpoint	Point2D	constant 2D point	required

Supplement()

Convert to supplementary arc

Orientation of arc will not be changed.

__eq__(arc)

Comparison of arcs without tolerance.

Be careful, this method work without tolerance!

Parameters:

Name	Type	Description	Default
arc	Arc2D	Compared arc.	required

Returns:

Type	Description
object	True when arcs are equal, otherwise false.

__init__ overload

__init__()

initialize

__init__(arc)

Copy constructor.

Parameters:

Name	Type	Description	Default
arc	Arc2D	Arc2D to be copied	required

__init__(center, minor, major, axisangle, startangle, endangle, counterClockwise=True)

Constructor

Parameters:

Name	Type	Description	Default
center	Point2D	Center point	required
minor	float	Minor radius	required
major	float	Major radius	required
axisangle	float	Axis angle	required
startangle	float	Start angle	required
endangle	float	End angle	required
counterClockwise	bool	Direction is counter clockwise: true/false	True

__init__(center, radius, counterClockwise=True)

Constructor for creating circle

Create circle as arc with start angle 0 [rad] and end angle 2pi [rad]. Minor and major radii are equal.

Parameters:

Name	Type	Description	Default
center	Point2D	Center point	required
radius	float	Minor radius	required
counterClockwise	bool	Direction is counter clockwise: true/false	True

__mul__(matrix)

Matrix transformation.

Parameters:

Name	Type	Description	Default
matrix	Matrix2D	transformation matrix.	required

Returns:

Type	Description
Arc2D	transformed Arc2D.

__repr__()

Convert to string