Arc¶

ARC (DXF Reference) center at location dxf.center and radius of dxf.radius from dxf.start_angle to dxf.end_angle. ARC goes always from dxf.start_angle to dxf.end_angle in counter clockwise orientation around the dxf.extrusion vector, which is (0, 0, 1) by default and the usual case for 2D arcs. The ARC entity has OCS coordinates.

The helper tool ezdxf.math.ConstructionArc supports creating arcs from various scenarios, like from 3 points or 2 points and an angle or 2 points and a radius.

See also

Subclass of	`ezdxf.entities.Circle`
DXF type	`'ARC'`
Factory function	`ezdxf.layouts.BaseLayout.add_arc()`
Inherited DXF attributes	Common graphical DXF attributes

Warning

Do not instantiate entity classes by yourself - always use the provided factory functions!

class ezdxf.entities.Arc¶

dxf.center¶: Center point of arc (2D/3D Point in OCS)

dxf.radius¶: Radius of arc (float)

dxf.start_angle¶: Start angle in degrees (float)

dxf.end_angle¶: End angle in degrees (float)

start_point¶: Returns the start point of the arc in WCS, takes OCS into account.

end_point¶: Returns the end point of the arc in WCS, takes OCS into account.

angles(num: int) → Iterable[float]¶

Returns num angles from start- to end angle in degrees in counter-clockwise orientation.

All angles are normalized in the range from [0, 360).

flattening(sagitta: float) → Iterator[Vec3]¶: Approximate the arc by vertices in WCS, argument segment is the max. distance from the center of an arc segment to the center of its chord.

transform(m: Matrix44) → Arc¶

Transform ARC entity by transformation matrix m inplace.

Raises NonUniformScalingError() for non uniform scaling.

to_ellipse(replace=True) → Ellipse¶

Convert CIRCLE/ARC to an Ellipse entity.

Adds the new ELLIPSE entity to the entity database and to the same layout as the source entity.

Parameters: replace – replace (delete) source entity by ELLIPSE entity if True

to_spline(replace=True) → Spline¶

Convert CIRCLE/ARC to a Spline entity.

Adds the new SPLINE entity to the entity database and to the same layout as the source entity.

Parameters: replace – replace (delete) source entity by SPLINE entity if True

construction_tool() → ConstructionArc¶: Returns 2D construction tool ezdxf.math.ConstructionArc, ignoring the extrusion vector.

apply_construction_tool(arc: ConstructionArc) → Arc¶: Set ARC data from construction tool ezdxf.math.ConstructionArc, will not change the extrusion vector.