Line

class compas.geometry.Line

Bases: Curve

A line is a curve defined by two points.

The first point is the start point of the line. The second point is the end point of the line. The vector between the two points defines the direction of the line. The length of the vector is the length of the line. The direction vector is the unit vector of the vector between start and end. The parameterisation of the line is such that the start point corresponds to t = 0 and the end point to t = 1.

The coordinate system of a line is always the world coordinate system (WCS). Transformation of a line is performed by transforming the start and end point.

Parameters:

start[float, float, float] | compas.geometry.Point

The first point.

end[float, float, float] | compas.geometry.Point

The second point.

namestr, optional

The name of the line.

Attributes:

startcompas.geometry.Point

The start point of the line.

endcompas.geometry.Point

The end point of the line.

vectorcompas.geometry.Vector, read-only

A vector pointing from start to end.

lengthfloat, read-only

Compute the length of the curve.

directioncompas.geometry.Vector, read-only

A unit vector parallel to the line vector.

midpointcompas.geometry.Point, read-only

The midpoint between start and end.

framecompas.geometry.Frame, read-only

The frame of the line. This is alsways the world XY frame.

transformationcompas.geometry.Transformation, read-only

This is always the identity transformation.

Examples

>>> line = Line([0, 0, 0], [1, 1, 1])
>>> print(line.start)
Point(x=0.000, y=0.000, z=0.000)
>>> print(line.midpoint)
Point(x=0.500, y=0.500, z=0.500)
>>> line.length == line.vector.length
True
>>> print(line.direction)
Vector(x=0.577, y=0.577, z=0.577)

Methods

closest_point	Compute the closest point on the line to a given point.
flip	Flip the direction of the line.
flipped	Return a new line with the direction flipped.
from_point_and_vector	Construct a line from a point and a vector.
from_point_direction_length	Construct a line from a point, a direction and a length.
point_at	Construct a point along the line at a fractional position.
point_from_end	Construct a point along the line at a distance from the end point.
point_from_start	Construct a point along the line at a distance from the start point.
transform	Transform this line.

Inherited Methods

ToString	Converts the instance to a string.
aabb	Compute the axis-aligned bounding box of the curve.
compute_aabb	Compute the axis-aligned bounding box of the geometry.
compute_obb	Compute the oriented bounding box of the geometry.
copy	Make an independent copy of the data object.
curvature_at	Compute the curvature vector of the curve at a parameter.
divide_by_count	Compute the curve parameters that divide the curve into a specific number of equal length segments.
divide_by_length	Compute the curve parameters that divide the curve into segments of specified length.
fair
frame_at	Compute the local frame of the curve at a parameter.
from_json	Construct an object of this type from a JSON file.
from_jsonstring	Construct an object of this type from a JSON string.
from_native	Construct a parametric curve from a native curve geometry.
from_obj	Load a curve from an OBJ file.
from_step	Load a curve from a STP file.
normal_at	Compute the normal of the curve at a parameter.
offset
reverse	Reverse the parametrisation of the curve.
reversed	Reverse a copy of the curve.
rotate	Rotate the geometry.
rotated	Returns a rotated copy of this geometry.
scale	Scale the geometry.
scaled	Returns a scaled copy of this geometry.
sha256	Compute a hash of the data for comparison during version control using the sha256 algorithm.
smooth
split
tangent_at	Compute the tangent vector of the curve at a parameter.
to_json	Convert an object to its native data representation and save it to a JSON file.
to_jsonstring	Convert an object to its native data representation and save it to a JSON string.
to_obj	Write the curve geometry to an OBJ file.
to_points	Convert the curve to a list of points.
to_polygon	Convert the curve to a polygon.
to_polyline	Convert the curve to a polyline.
to_step	Write the curve geometry to a STP file.
transformed	Returns a transformed copy of this geometry.
translate	Translate the geometry.
translated	Returns a translated copy of this geometry.
trim
validate_data	Validate the data against the object's data schema.