Lines¶
-
class
sympy.geometry.line.
LinearEntity
[source]¶ A base class for all linear entities (Line, Ray and Segment) in n-dimensional Euclidean space.
Notes
This is an abstract class and is not meant to be instantiated.
See also
Attributes
ambient_dimension
direction
length
p1
p2
points
-
ambient_dimension
¶ A property method that returns the dimension of LinearEntity object.
- Parameters
p1 : LinearEntity
- Returns
dimension : integer
Examples
>>> from sympy import Point, Line >>> p1, p2 = Point(0, 0), Point(1, 1) >>> l1 = Line(p1, p2) >>> l1.ambient_dimension 2
>>> from sympy import Point, Line >>> p1, p2 = Point(0, 0, 0), Point(1, 1, 1) >>> l1 = Line(p1, p2) >>> l1.ambient_dimension 3
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angle_between
(l2)[source]¶ Return the non-reflex angle formed by rays emanating from the origin with directions the same as the direction vectors of the linear entities.
- Parameters
l1 : LinearEntity
l2 : LinearEntity
- Returns
angle : angle in radians
Notes
From the dot product of vectors v1 and v2 it is known that:
dot(v1, v2) = |v1|*|v2|*cos(A)
where A is the angle formed between the two vectors. We can get the directional vectors of the two lines and readily find the angle between the two using the above formula.
Examples
>>> from sympy import Point, Line, pi >>> e = Line((0, 0), (1, 0)) >>> ne = Line((0, 0), (1, 1)) >>> sw = Line((1, 1), (0, 0)) >>> ne.angle_between(e) pi/4 >>> sw.angle_between(e) 3*pi/4
To obtain the non-obtuse angle at the intersection of lines, use the
smallest_angle_between
method:>>> sw.smallest_angle_between(e) pi/4
>>> from sympy import Point3D, Line3D >>> p1, p2, p3 = Point3D(0, 0, 0), Point3D(1, 1, 1), Point3D(-1, 2, 0) >>> l1, l2 = Line3D(p1, p2), Line3D(p2, p3) >>> l1.angle_between(l2) acos(-sqrt(2)/3) >>> l1.smallest_angle_between(l2) acos(sqrt(2)/3)
See also
-
arbitrary_point
(parameter='t')[source]¶ A parameterized point on the Line.
- Parameters
parameter : str, optional
The name of the parameter which will be used for the parametric point. The default value is ‘t’. When this parameter is 0, the first point used to define the line will be returned, and when it is 1 the second point will be returned.
- Returns
point : Point
- Raises
ValueError
When
parameter
already appears in the Line’s definition.
Examples
>>> from sympy import Point, Line >>> p1, p2 = Point(1, 0), Point(5, 3) >>> l1 = Line(p1, p2) >>> l1.arbitrary_point() Point2D(4*t + 1, 3*t) >>> from sympy import Point3D, Line3D >>> p1, p2 = Point3D(1, 0, 0), Point3D(5, 3, 1) >>> l1 = Line3D(p1, p2) >>> l1.arbitrary_point() Point3D(4*t + 1, 3*t, t)
See also
-
static
are_concurrent
(*lines)[source]¶ Is a sequence of linear entities concurrent?
Two or more linear entities are concurrent if they all intersect at a single point.
- Parameters
lines : a sequence of linear entities.
- Returns
True : if the set of linear entities intersect in one point
False : otherwise.
Examples
>>> from sympy import Point, Line, Line3D >>> p1, p2 = Point(0, 0), Point(3, 5) >>> p3, p4 = Point(-2, -2), Point(0, 2) >>> l1, l2, l3 = Line(p1, p2), Line(p1, p3), Line(p1, p4) >>> Line.are_concurrent(l1, l2, l3) True >>> l4 = Line(p2, p3) >>> Line.are_concurrent(l2, l3, l4) False >>> from sympy import Point3D, Line3D >>> p1, p2 = Point3D(0, 0, 0), Point3D(3, 5, 2) >>> p3, p4 = Point3D(-2, -2, -2), Point3D(0, 2, 1) >>> l1, l2, l3 = Line3D(p1, p2), Line3D(p1, p3), Line3D(p1, p4) >>> Line3D.are_concurrent(l1, l2, l3) True >>> l4 = Line3D(p2, p3) >>> Line3D.are_concurrent(l2, l3, l4) False
See also
-
contains
(other)[source]¶ Subclasses should implement this method and should return True if other is on the boundaries of self; False if not on the boundaries of self; None if a determination cannot be made.
-
direction
¶ The direction vector of the LinearEntity.
- Returns
p : a Point; the ray from the origin to this point is the
direction of \(self\)
Examples
>>> from sympy.geometry import Line >>> a, b = (1, 1), (1, 3) >>> Line(a, b).direction Point2D(0, 2) >>> Line(b, a).direction Point2D(0, -2)
This can be reported so the distance from the origin is 1:
>>> Line(b, a).direction.unit Point2D(0, -1)
See also
-
intersection
(other)[source]¶ The intersection with another geometrical entity.
- Parameters
o : Point or LinearEntity
- Returns
intersection : list of geometrical entities
Examples
>>> from sympy import Point, Line, Segment >>> p1, p2, p3 = Point(0, 0), Point(1, 1), Point(7, 7) >>> l1 = Line(p1, p2) >>> l1.intersection(p3) [Point2D(7, 7)] >>> p4, p5 = Point(5, 0), Point(0, 3) >>> l2 = Line(p4, p5) >>> l1.intersection(l2) [Point2D(15/8, 15/8)] >>> p6, p7 = Point(0, 5), Point(2, 6) >>> s1 = Segment(p6, p7) >>> l1.intersection(s1) [] >>> from sympy import Point3D, Line3D, Segment3D >>> p1, p2, p3 = Point3D(0, 0, 0), Point3D(1, 1, 1), Point3D(7, 7, 7) >>> l1 = Line3D(p1, p2) >>> l1.intersection(p3) [Point3D(7, 7, 7)] >>> l1 = Line3D(Point3D(4,19,12), Point3D(5,25,17)) >>> l2 = Line3D(Point3D(-3, -15, -19), direction_ratio=[2,8,8]) >>> l1.intersection(l2) [Point3D(1, 1, -3)] >>> p6, p7 = Point3D(0, 5, 2), Point3D(2, 6, 3) >>> s1 = Segment3D(p6, p7) >>> l1.intersection(s1) []
See also
-
is_parallel
(l2)[source]¶ Are two linear entities parallel?
- Parameters
l1 : LinearEntity
l2 : LinearEntity
- Returns
True : if l1 and l2 are parallel,
False : otherwise.
Examples
>>> from sympy import Point, Line >>> p1, p2 = Point(0, 0), Point(1, 1) >>> p3, p4 = Point(3, 4), Point(6, 7) >>> l1, l2 = Line(p1, p2), Line(p3, p4) >>> Line.is_parallel(l1, l2) True >>> p5 = Point(6, 6) >>> l3 = Line(p3, p5) >>> Line.is_parallel(l1, l3) False >>> from sympy import Point3D, Line3D >>> p1, p2 = Point3D(0, 0, 0), Point3D(3, 4, 5) >>> p3, p4 = Point3D(2, 1, 1), Point3D(8, 9, 11) >>> l1, l2 = Line3D(p1, p2), Line3D(p3, p4) >>> Line3D.is_parallel(l1, l2) True >>> p5 = Point3D(6, 6, 6) >>> l3 = Line3D(p3, p5) >>> Line3D.is_parallel(l1, l3) False
See also
coefficients
-
is_perpendicular
(l2)[source]¶ Are two linear entities perpendicular?
- Parameters
l1 : LinearEntity
l2 : LinearEntity
- Returns
True : if l1 and l2 are perpendicular,
False : otherwise.
Examples
>>> from sympy import Point, Line >>> p1, p2, p3 = Point(0, 0), Point(1, 1), Point(-1, 1) >>> l1, l2 = Line(p1, p2), Line(p1, p3) >>> l1.is_perpendicular(l2) True >>> p4 = Point(5, 3) >>> l3 = Line(p1, p4) >>> l1.is_perpendicular(l3) False >>> from sympy import Point3D, Line3D >>> p1, p2, p3 = Point3D(0, 0, 0), Point3D(1, 1, 1), Point3D(-1, 2, 0) >>> l1, l2 = Line3D(p1, p2), Line3D(p2, p3) >>> l1.is_perpendicular(l2) False >>> p4 = Point3D(5, 3, 7) >>> l3 = Line3D(p1, p4) >>> l1.is_perpendicular(l3) False
See also
coefficients
-
is_similar
(other)[source]¶ Return True if self and other are contained in the same line.
Examples
>>> from sympy import Point, Line >>> p1, p2, p3 = Point(0, 1), Point(3, 4), Point(2, 3) >>> l1 = Line(p1, p2) >>> l2 = Line(p1, p3) >>> l1.is_similar(l2) True
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length
¶ The length of the line.
Examples
>>> from sympy import Point, Line >>> p1, p2 = Point(0, 0), Point(3, 5) >>> l1 = Line(p1, p2) >>> l1.length oo
-
p1
¶ The first defining point of a linear entity.
Examples
>>> from sympy import Point, Line >>> p1, p2 = Point(0, 0), Point(5, 3) >>> l = Line(p1, p2) >>> l.p1 Point2D(0, 0)
See also
-
p2
¶ The second defining point of a linear entity.
Examples
>>> from sympy import Point, Line >>> p1, p2 = Point(0, 0), Point(5, 3) >>> l = Line(p1, p2) >>> l.p2 Point2D(5, 3)
See also
-
parallel_line
(p)[source]¶ Create a new Line parallel to this linear entity which passes through the point \(p\).
- Parameters
p : Point
- Returns
line : Line
Examples
>>> from sympy import Point, Line >>> p1, p2, p3 = Point(0, 0), Point(2, 3), Point(-2, 2) >>> l1 = Line(p1, p2) >>> l2 = l1.parallel_line(p3) >>> p3 in l2 True >>> l1.is_parallel(l2) True >>> from sympy import Point3D, Line3D >>> p1, p2, p3 = Point3D(0, 0, 0), Point3D(2, 3, 4), Point3D(-2, 2, 0) >>> l1 = Line3D(p1, p2) >>> l2 = l1.parallel_line(p3) >>> p3 in l2 True >>> l1.is_parallel(l2) True
See also
-
perpendicular_line
(p)[source]¶ Create a new Line perpendicular to this linear entity which passes through the point \(p\).
- Parameters
p : Point
- Returns
line : Line
Examples
>>> from sympy import Point, Line >>> p1, p2, p3 = Point(0, 0), Point(2, 3), Point(-2, 2) >>> l1 = Line(p1, p2) >>> l2 = l1.perpendicular_line(p3) >>> p3 in l2 True >>> l1.is_perpendicular(l2) True >>> from sympy import Point3D, Line3D >>> p1, p2, p3 = Point3D(0, 0, 0), Point3D(2, 3, 4), Point3D(-2, 2, 0) >>> l1 = Line3D(p1, p2) >>> l2 = l1.perpendicular_line(p3) >>> p3 in l2 True >>> l1.is_perpendicular(l2) True
See also
-
perpendicular_segment
(p)[source]¶ Create a perpendicular line segment from \(p\) to this line.
The enpoints of the segment are
p
and the closest point in the line containing self. (If self is not a line, the point might not be in self.)- Parameters
p : Point
- Returns
segment : Segment
Notes
Returns \(p\) itself if \(p\) is on this linear entity.
Examples
>>> from sympy import Point, Line >>> p1, p2, p3 = Point(0, 0), Point(1, 1), Point(0, 2) >>> l1 = Line(p1, p2) >>> s1 = l1.perpendicular_segment(p3) >>> l1.is_perpendicular(s1) True >>> p3 in s1 True >>> l1.perpendicular_segment(Point(4, 0)) Segment2D(Point2D(4, 0), Point2D(2, 2)) >>> from sympy import Point3D, Line3D >>> p1, p2, p3 = Point3D(0, 0, 0), Point3D(1, 1, 1), Point3D(0, 2, 0) >>> l1 = Line3D(p1, p2) >>> s1 = l1.perpendicular_segment(p3) >>> l1.is_perpendicular(s1) True >>> p3 in s1 True >>> l1.perpendicular_segment(Point3D(4, 0, 0)) Segment3D(Point3D(4, 0, 0), Point3D(4/3, 4/3, 4/3))
See also
-
points
¶ The two points used to define this linear entity.
- Returns
points : tuple of Points
Examples
>>> from sympy import Point, Line >>> p1, p2 = Point(0, 0), Point(5, 11) >>> l1 = Line(p1, p2) >>> l1.points (Point2D(0, 0), Point2D(5, 11))
See also
-
projection
(other)[source]¶ Project a point, line, ray, or segment onto this linear entity.
- Parameters
other : Point or LinearEntity (Line, Ray, Segment)
- Returns
projection : Point or LinearEntity (Line, Ray, Segment)
The return type matches the type of the parameter
other
.- Raises
GeometryError
When method is unable to perform projection.
Notes
A projection involves taking the two points that define the linear entity and projecting those points onto a Line and then reforming the linear entity using these projections. A point P is projected onto a line L by finding the point on L that is closest to P. This point is the intersection of L and the line perpendicular to L that passes through P.
Examples
>>> from sympy import Point, Line, Segment, Rational >>> p1, p2, p3 = Point(0, 0), Point(1, 1), Point(Rational(1, 2), 0) >>> l1 = Line(p1, p2) >>> l1.projection(p3) Point2D(1/4, 1/4) >>> p4, p5 = Point(10, 0), Point(12, 1) >>> s1 = Segment(p4, p5) >>> l1.projection(s1) Segment2D(Point2D(5, 5), Point2D(13/2, 13/2)) >>> p1, p2, p3 = Point(0, 0, 1), Point(1, 1, 2), Point(2, 0, 1) >>> l1 = Line(p1, p2) >>> l1.projection(p3) Point3D(2/3, 2/3, 5/3) >>> p4, p5 = Point(10, 0, 1), Point(12, 1, 3) >>> s1 = Segment(p4, p5) >>> l1.projection(s1) Segment3D(Point3D(10/3, 10/3, 13/3), Point3D(5, 5, 6))
See also
-
random_point
(seed=None)[source]¶ A random point on a LinearEntity.
- Returns
point : Point
Examples
>>> from sympy import Point, Line, Ray, Segment >>> p1, p2 = Point(0, 0), Point(5, 3) >>> line = Line(p1, p2) >>> r = line.random_point(seed=42) # seed value is optional >>> r.n(3) Point2D(-0.72, -0.432) >>> r in line True >>> Ray(p1, p2).random_point(seed=42).n(3) Point2D(0.72, 0.432) >>> Segment(p1, p2).random_point(seed=42).n(3) Point2D(3.2, 1.92)
See also
-
smallest_angle_between
(l2)[source]¶ Return the smallest angle formed at the intersection of the lines containing the linear entities.
- Parameters
l1 : LinearEntity
l2 : LinearEntity
- Returns
angle : angle in radians
Examples
>>> from sympy import Point, Line, pi >>> p1, p2, p3 = Point(0, 0), Point(0, 4), Point(2, -2) >>> l1, l2 = Line(p1, p2), Line(p1, p3) >>> l1.smallest_angle_between(l2) pi/4
See also
-
-
class
sympy.geometry.line.
Line
[source]¶ An infinite line in space.
A 2D line is declared with two distinct points, point and slope, or an equation. A 3D line may be defined with a point and a direction ratio.
- Parameters
p1 : Point
p2 : Point
slope : sympy expression
direction_ratio : list
equation : equation of a line
Notes
\(Line\) will automatically subclass to \(Line2D\) or \(Line3D\) based on the dimension of \(p1\). The \(slope\) argument is only relevant for \(Line2D\) and the \(direction_ratio\) argument is only relevant for \(Line3D\).
Examples
>>> from sympy import Point, Eq >>> from sympy.geometry import Line, Segment >>> from sympy.abc import x, y, a, b
>>> L = Line(Point(2,3), Point(3,5)) >>> L Line2D(Point2D(2, 3), Point2D(3, 5)) >>> L.points (Point2D(2, 3), Point2D(3, 5)) >>> L.equation() -2*x + y + 1 >>> L.coefficients (-2, 1, 1)
Instantiate with keyword
slope
:>>> Line(Point(0, 0), slope=0) Line2D(Point2D(0, 0), Point2D(1, 0))
Instantiate with another linear object
>>> s = Segment((0, 0), (0, 1)) >>> Line(s).equation() x
The line corresponding to an equation in the for \(ax + by + c = 0\), can be entered:
>>> Line(3*x + y + 18) Line2D(Point2D(0, -18), Point2D(1, -21))
If \(x\) or \(y\) has a different name, then they can be specified, too, as a string (to match the name) or symbol:
>>> Line(Eq(3*a + b, -18), x='a', y=b) Line2D(Point2D(0, -18), Point2D(1, -21))
-
contains
(other)[source]¶ Return True if \(other\) is on this Line, or False otherwise.
Examples
>>> from sympy import Line,Point >>> p1, p2 = Point(0, 1), Point(3, 4) >>> l = Line(p1, p2) >>> l.contains(p1) True >>> l.contains((0, 1)) True >>> l.contains((0, 0)) False >>> a = (0, 0, 0) >>> b = (1, 1, 1) >>> c = (2, 2, 2) >>> l1 = Line(a, b) >>> l2 = Line(b, a) >>> l1 == l2 False >>> l1 in l2 True
-
distance
(other)[source]¶ Finds the shortest distance between a line and a point.
- Raises
NotImplementedError is raised if `other` is not a Point
Examples
>>> from sympy import Point, Line >>> p1, p2 = Point(0, 0), Point(1, 1) >>> s = Line(p1, p2) >>> s.distance(Point(-1, 1)) sqrt(2) >>> s.distance((-1, 2)) 3*sqrt(2)/2 >>> p1, p2 = Point(0, 0, 0), Point(1, 1, 1) >>> s = Line(p1, p2) >>> s.distance(Point(-1, 1, 1)) 2*sqrt(6)/3 >>> s.distance((-1, 1, 1)) 2*sqrt(6)/3
-
plot_interval
(parameter='t')[source]¶ The plot interval for the default geometric plot of line. Gives values that will produce a line that is +/- 5 units long (where a unit is the distance between the two points that define the line).
- Parameters
parameter : str, optional
Default value is ‘t’.
- Returns
plot_interval : list (plot interval)
[parameter, lower_bound, upper_bound]
Examples
>>> from sympy import Point, Line >>> p1, p2 = Point(0, 0), Point(5, 3) >>> l1 = Line(p1, p2) >>> l1.plot_interval() [t, -5, 5]
-
class
sympy.geometry.line.
Ray
[source]¶ A Ray is a semi-line in the space with a source point and a direction.
- Parameters
p1 : Point
The source of the Ray
p2 : Point or radian value
This point determines the direction in which the Ray propagates. If given as an angle it is interpreted in radians with the positive direction being ccw.
Notes
\(Ray\) will automatically subclass to \(Ray2D\) or \(Ray3D\) based on the dimension of \(p1\).
Examples
>>> from sympy import Point, pi >>> from sympy.geometry import Ray >>> r = Ray(Point(2, 3), Point(3, 5)) >>> r Ray2D(Point2D(2, 3), Point2D(3, 5)) >>> r.points (Point2D(2, 3), Point2D(3, 5)) >>> r.source Point2D(2, 3) >>> r.xdirection oo >>> r.ydirection oo >>> r.slope 2 >>> Ray(Point(0, 0), angle=pi/4).slope 1
See also
sympy.geometry.line.Ray2D
,sympy.geometry.line.Ray3D
,sympy.geometry.point.Point
,sympy.geometry.line.Line
Attributes
source
-
contains
(other)[source]¶ Is other GeometryEntity contained in this Ray?
Examples
>>> from sympy import Ray,Point,Segment >>> p1, p2 = Point(0, 0), Point(4, 4) >>> r = Ray(p1, p2) >>> r.contains(p1) True >>> r.contains((1, 1)) True >>> r.contains((1, 3)) False >>> s = Segment((1, 1), (2, 2)) >>> r.contains(s) True >>> s = Segment((1, 2), (2, 5)) >>> r.contains(s) False >>> r1 = Ray((2, 2), (3, 3)) >>> r.contains(r1) True >>> r1 = Ray((2, 2), (3, 5)) >>> r.contains(r1) False
-
distance
(other)[source]¶ Finds the shortest distance between the ray and a point.
- Raises
NotImplementedError is raised if `other` is not a Point
Examples
>>> from sympy import Point, Ray >>> p1, p2 = Point(0, 0), Point(1, 1) >>> s = Ray(p1, p2) >>> s.distance(Point(-1, -1)) sqrt(2) >>> s.distance((-1, 2)) 3*sqrt(2)/2 >>> p1, p2 = Point(0, 0, 0), Point(1, 1, 2) >>> s = Ray(p1, p2) >>> s Ray3D(Point3D(0, 0, 0), Point3D(1, 1, 2)) >>> s.distance(Point(-1, -1, 2)) 4*sqrt(3)/3 >>> s.distance((-1, -1, 2)) 4*sqrt(3)/3
-
plot_interval
(parameter='t')[source]¶ The plot interval for the default geometric plot of the Ray. Gives values that will produce a ray that is 10 units long (where a unit is the distance between the two points that define the ray).
- Parameters
parameter : str, optional
Default value is ‘t’.
- Returns
plot_interval : list
[parameter, lower_bound, upper_bound]
Examples
>>> from sympy import Ray, pi >>> r = Ray((0, 0), angle=pi/4) >>> r.plot_interval() [t, 0, 10]
-
source
¶ The point from which the ray emanates.
Examples
>>> from sympy import Point, Ray >>> p1, p2 = Point(0, 0), Point(4, 1) >>> r1 = Ray(p1, p2) >>> r1.source Point2D(0, 0) >>> p1, p2 = Point(0, 0, 0), Point(4, 1, 5) >>> r1 = Ray(p2, p1) >>> r1.source Point3D(4, 1, 5)
See also
-
class
sympy.geometry.line.
Segment
[source]¶ A line segment in space.
- Parameters
p1 : Point
p2 : Point
Notes
If 2D or 3D points are used to define \(Segment\), it will be automatically subclassed to \(Segment2D\) or \(Segment3D\).
Examples
>>> from sympy import Point >>> from sympy.geometry import Segment >>> Segment((1, 0), (1, 1)) # tuples are interpreted as pts Segment2D(Point2D(1, 0), Point2D(1, 1)) >>> s = Segment(Point(4, 3), Point(1, 1)) >>> s.points (Point2D(4, 3), Point2D(1, 1)) >>> s.slope 2/3 >>> s.length sqrt(13) >>> s.midpoint Point2D(5/2, 2) >>> Segment((1, 0, 0), (1, 1, 1)) # tuples are interpreted as pts Segment3D(Point3D(1, 0, 0), Point3D(1, 1, 1)) >>> s = Segment(Point(4, 3, 9), Point(1, 1, 7)); s Segment3D(Point3D(4, 3, 9), Point3D(1, 1, 7)) >>> s.points (Point3D(4, 3, 9), Point3D(1, 1, 7)) >>> s.length sqrt(17) >>> s.midpoint Point3D(5/2, 2, 8)
See also
sympy.geometry.line.Segment2D
,sympy.geometry.line.Segment3D
,sympy.geometry.point.Point
,sympy.geometry.line.Line
Attributes
length
(number or sympy expression)
midpoint
(Point)
-
contains
(other)[source]¶ Is the other GeometryEntity contained within this Segment?
Examples
>>> from sympy import Point, Segment >>> p1, p2 = Point(0, 1), Point(3, 4) >>> s = Segment(p1, p2) >>> s2 = Segment(p2, p1) >>> s.contains(s2) True >>> from sympy import Point3D, Segment3D >>> p1, p2 = Point3D(0, 1, 1), Point3D(3, 4, 5) >>> s = Segment3D(p1, p2) >>> s2 = Segment3D(p2, p1) >>> s.contains(s2) True >>> s.contains((p1 + p2) / 2) True
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distance
(other)[source]¶ Finds the shortest distance between a line segment and a point.
- Raises
NotImplementedError is raised if `other` is not a Point
Examples
>>> from sympy import Point, Segment >>> p1, p2 = Point(0, 1), Point(3, 4) >>> s = Segment(p1, p2) >>> s.distance(Point(10, 15)) sqrt(170) >>> s.distance((0, 12)) sqrt(73) >>> from sympy import Point3D, Segment3D >>> p1, p2 = Point3D(0, 0, 3), Point3D(1, 1, 4) >>> s = Segment3D(p1, p2) >>> s.distance(Point3D(10, 15, 12)) sqrt(341) >>> s.distance((10, 15, 12)) sqrt(341)
-
length
¶ The length of the line segment.
Examples
>>> from sympy import Point, Segment >>> p1, p2 = Point(0, 0), Point(4, 3) >>> s1 = Segment(p1, p2) >>> s1.length 5 >>> from sympy import Point3D, Segment3D >>> p1, p2 = Point3D(0, 0, 0), Point3D(4, 3, 3) >>> s1 = Segment3D(p1, p2) >>> s1.length sqrt(34)
See also
-
midpoint
¶ The midpoint of the line segment.
Examples
>>> from sympy import Point, Segment >>> p1, p2 = Point(0, 0), Point(4, 3) >>> s1 = Segment(p1, p2) >>> s1.midpoint Point2D(2, 3/2) >>> from sympy import Point3D, Segment3D >>> p1, p2 = Point3D(0, 0, 0), Point3D(4, 3, 3) >>> s1 = Segment3D(p1, p2) >>> s1.midpoint Point3D(2, 3/2, 3/2)
See also
-
perpendicular_bisector
(p=None)[source]¶ The perpendicular bisector of this segment.
If no point is specified or the point specified is not on the bisector then the bisector is returned as a Line. Otherwise a Segment is returned that joins the point specified and the intersection of the bisector and the segment.
- Parameters
p : Point
- Returns
bisector : Line or Segment
Examples
>>> from sympy import Point, Segment >>> p1, p2, p3 = Point(0, 0), Point(6, 6), Point(5, 1) >>> s1 = Segment(p1, p2) >>> s1.perpendicular_bisector() Line2D(Point2D(3, 3), Point2D(-3, 9))
>>> s1.perpendicular_bisector(p3) Segment2D(Point2D(5, 1), Point2D(3, 3))
See also
-
plot_interval
(parameter='t')[source]¶ The plot interval for the default geometric plot of the Segment gives values that will produce the full segment in a plot.
- Parameters
parameter : str, optional
Default value is ‘t’.
- Returns
plot_interval : list
[parameter, lower_bound, upper_bound]
Examples
>>> from sympy import Point, Segment >>> p1, p2 = Point(0, 0), Point(5, 3) >>> s1 = Segment(p1, p2) >>> s1.plot_interval() [t, 0, 1]
-
class
sympy.geometry.line.
LinearEntity2D
[source]¶ A base class for all linear entities (line, ray and segment) in a 2-dimensional Euclidean space.
Notes
This is an abstract class and is not meant to be instantiated.
See also
Attributes
p1
p2
coefficients
slope
points
-
bounds
¶ Return a tuple (xmin, ymin, xmax, ymax) representing the bounding rectangle for the geometric figure.
-
perpendicular_line
(p)[source]¶ Create a new Line perpendicular to this linear entity which passes through the point \(p\).
- Parameters
p : Point
- Returns
line : Line
Examples
>>> from sympy import Point, Line >>> p1, p2, p3 = Point(0, 0), Point(2, 3), Point(-2, 2) >>> l1 = Line(p1, p2) >>> l2 = l1.perpendicular_line(p3) >>> p3 in l2 True >>> l1.is_perpendicular(l2) True
See also
is_perpendicular
,perpendicular_segment
-
slope
¶ The slope of this linear entity, or infinity if vertical.
- Returns
slope : number or sympy expression
Examples
>>> from sympy import Point, Line >>> p1, p2 = Point(0, 0), Point(3, 5) >>> l1 = Line(p1, p2) >>> l1.slope 5/3
>>> p3 = Point(0, 4) >>> l2 = Line(p1, p3) >>> l2.slope oo
See also
coefficients
-
-
class
sympy.geometry.line.
Line2D
[source]¶ An infinite line in space 2D.
A line is declared with two distinct points or a point and slope as defined using keyword \(slope\).
- Parameters
p1 : Point
pt : Point
slope : sympy expression
Examples
>>> from sympy import Point >>> from sympy.abc import L >>> from sympy.geometry import Line, Segment >>> L = Line(Point(2,3), Point(3,5)) >>> L Line2D(Point2D(2, 3), Point2D(3, 5)) >>> L.points (Point2D(2, 3), Point2D(3, 5)) >>> L.equation() -2*x + y + 1 >>> L.coefficients (-2, 1, 1)
Instantiate with keyword
slope
:>>> Line(Point(0, 0), slope=0) Line2D(Point2D(0, 0), Point2D(1, 0))
Instantiate with another linear object
>>> s = Segment((0, 0), (0, 1)) >>> Line(s).equation() x
See also
-
coefficients
¶ The coefficients (\(a\), \(b\), \(c\)) for \(ax + by + c = 0\).
Examples
>>> from sympy import Point, Line >>> from sympy.abc import x, y >>> p1, p2 = Point(0, 0), Point(5, 3) >>> l = Line(p1, p2) >>> l.coefficients (-3, 5, 0)
>>> p3 = Point(x, y) >>> l2 = Line(p1, p3) >>> l2.coefficients (-y, x, 0)
See also
sympy.geometry.line.Line.equation
-
equation
(x='x', y='y')[source]¶ The equation of the line: ax + by + c.
- Parameters
x : str, optional
The name to use for the x-axis, default value is ‘x’.
y : str, optional
The name to use for the y-axis, default value is ‘y’.
- Returns
equation : sympy expression
Examples
>>> from sympy import Point, Line >>> p1, p2 = Point(1, 0), Point(5, 3) >>> l1 = Line(p1, p2) >>> l1.equation() -3*x + 4*y + 3
See also
LinearEntity.coefficients
-
class
sympy.geometry.line.
Ray2D
[source]¶ A Ray is a semi-line in the space with a source point and a direction.
- Parameters
p1 : Point
The source of the Ray
p2 : Point or radian value
This point determines the direction in which the Ray propagates. If given as an angle it is interpreted in radians with the positive direction being ccw.
Examples
>>> from sympy import Point, pi >>> from sympy.geometry import Ray >>> r = Ray(Point(2, 3), Point(3, 5)) >>> r Ray2D(Point2D(2, 3), Point2D(3, 5)) >>> r.points (Point2D(2, 3), Point2D(3, 5)) >>> r.source Point2D(2, 3) >>> r.xdirection oo >>> r.ydirection oo >>> r.slope 2 >>> Ray(Point(0, 0), angle=pi/4).slope 1
See also
Attributes
source
xdirection
ydirection
-
closing_angle
(r2)[source]¶ Return the angle by which r2 must be rotated so it faces the same direction as r1.
- Parameters
r1 : Ray2D
r2 : Ray2D
- Returns
angle : angle in radians (ccw angle is positive)
Examples
>>> from sympy import Ray, pi >>> r1 = Ray((0, 0), (1, 0)) >>> r2 = r1.rotate(-pi/2) >>> angle = r1.closing_angle(r2); angle pi/2 >>> r2.rotate(angle).direction.unit == r1.direction.unit True >>> r2.closing_angle(r1) -pi/2
See also
-
xdirection
¶ The x direction of the ray.
Positive infinity if the ray points in the positive x direction, negative infinity if the ray points in the negative x direction, or 0 if the ray is vertical.
Examples
>>> from sympy import Point, Ray >>> p1, p2, p3 = Point(0, 0), Point(1, 1), Point(0, -1) >>> r1, r2 = Ray(p1, p2), Ray(p1, p3) >>> r1.xdirection oo >>> r2.xdirection 0
See also
-
ydirection
¶ The y direction of the ray.
Positive infinity if the ray points in the positive y direction, negative infinity if the ray points in the negative y direction, or 0 if the ray is horizontal.
Examples
>>> from sympy import Point, Ray >>> p1, p2, p3 = Point(0, 0), Point(-1, -1), Point(-1, 0) >>> r1, r2 = Ray(p1, p2), Ray(p1, p3) >>> r1.ydirection -oo >>> r2.ydirection 0
See also
-
class
sympy.geometry.line.
Segment2D
[source]¶ A line segment in 2D space.
- Parameters
p1 : Point
p2 : Point
Examples
>>> from sympy import Point >>> from sympy.geometry import Segment >>> Segment((1, 0), (1, 1)) # tuples are interpreted as pts Segment2D(Point2D(1, 0), Point2D(1, 1)) >>> s = Segment(Point(4, 3), Point(1, 1)); s Segment2D(Point2D(4, 3), Point2D(1, 1)) >>> s.points (Point2D(4, 3), Point2D(1, 1)) >>> s.slope 2/3 >>> s.length sqrt(13) >>> s.midpoint Point2D(5/2, 2)
See also
Attributes
length
(number or sympy expression)
midpoint
(Point)
-
class
sympy.geometry.line.
LinearEntity3D
[source]¶ An base class for all linear entities (line, ray and segment) in a 3-dimensional Euclidean space.
Notes
This is a base class and is not meant to be instantiated.
Attributes
p1
p2
direction_ratio
direction_cosine
points
-
direction_cosine
¶ The normalized direction ratio of a given line in 3D.
Examples
>>> from sympy import Point3D, Line3D >>> p1, p2 = Point3D(0, 0, 0), Point3D(5, 3, 1) >>> l = Line3D(p1, p2) >>> l.direction_cosine [sqrt(35)/7, 3*sqrt(35)/35, sqrt(35)/35] >>> sum(i**2 for i in _) 1
See also
sympy.geometry.line.Line.equation
-
direction_ratio
¶ The direction ratio of a given line in 3D.
Examples
>>> from sympy import Point3D, Line3D >>> p1, p2 = Point3D(0, 0, 0), Point3D(5, 3, 1) >>> l = Line3D(p1, p2) >>> l.direction_ratio [5, 3, 1]
See also
sympy.geometry.line.Line.equation
-
-
class
sympy.geometry.line.
Line3D
[source]¶ An infinite 3D line in space.
A line is declared with two distinct points or a point and direction_ratio as defined using keyword \(direction_ratio\).
- Parameters
p1 : Point3D
pt : Point3D
direction_ratio : list
Examples
>>> from sympy import Point3D >>> from sympy.geometry import Line3D, Segment3D >>> L = Line3D(Point3D(2, 3, 4), Point3D(3, 5, 1)) >>> L Line3D(Point3D(2, 3, 4), Point3D(3, 5, 1)) >>> L.points (Point3D(2, 3, 4), Point3D(3, 5, 1))
-
equation
(x='x', y='y', z='z', k=None)[source]¶ Return the equations that define the line in 3D.
- Parameters
x : str, optional
The name to use for the x-axis, default value is ‘x’.
y : str, optional
The name to use for the y-axis, default value is ‘y’.
z : str, optional
The name to use for the z-axis, default value is ‘z’.
- Returns
equation : Tuple of simultaneous equations
Examples
>>> from sympy import Point3D, Line3D, solve >>> from sympy.abc import x, y, z >>> p1, p2 = Point3D(1, 0, 0), Point3D(5, 3, 0) >>> l1 = Line3D(p1, p2) >>> eq = l1.equation(x, y, z); eq (-3*x + 4*y + 3, z) >>> solve(eq.subs(z, 0), (x, y, z)) {x: 4*y/3 + 1}
-
class
sympy.geometry.line.
Ray3D
[source]¶ A Ray is a semi-line in the space with a source point and a direction.
- Parameters
p1 : Point3D
The source of the Ray
p2 : Point or a direction vector
direction_ratio: Determines the direction in which the Ray propagates.
Examples
>>> from sympy import Point3D >>> from sympy.geometry import Ray3D >>> r = Ray3D(Point3D(2, 3, 4), Point3D(3, 5, 0)) >>> r Ray3D(Point3D(2, 3, 4), Point3D(3, 5, 0)) >>> r.points (Point3D(2, 3, 4), Point3D(3, 5, 0)) >>> r.source Point3D(2, 3, 4) >>> r.xdirection oo >>> r.ydirection oo >>> r.direction_ratio [1, 2, -4]
See also
Attributes
source
xdirection
ydirection
zdirection
-
xdirection
¶ The x direction of the ray.
Positive infinity if the ray points in the positive x direction, negative infinity if the ray points in the negative x direction, or 0 if the ray is vertical.
Examples
>>> from sympy import Point3D, Ray3D >>> p1, p2, p3 = Point3D(0, 0, 0), Point3D(1, 1, 1), Point3D(0, -1, 0) >>> r1, r2 = Ray3D(p1, p2), Ray3D(p1, p3) >>> r1.xdirection oo >>> r2.xdirection 0
See also
-
ydirection
¶ The y direction of the ray.
Positive infinity if the ray points in the positive y direction, negative infinity if the ray points in the negative y direction, or 0 if the ray is horizontal.
Examples
>>> from sympy import Point3D, Ray3D >>> p1, p2, p3 = Point3D(0, 0, 0), Point3D(-1, -1, -1), Point3D(-1, 0, 0) >>> r1, r2 = Ray3D(p1, p2), Ray3D(p1, p3) >>> r1.ydirection -oo >>> r2.ydirection 0
See also
-
zdirection
¶ The z direction of the ray.
Positive infinity if the ray points in the positive z direction, negative infinity if the ray points in the negative z direction, or 0 if the ray is horizontal.
Examples
>>> from sympy import Point3D, Ray3D >>> p1, p2, p3 = Point3D(0, 0, 0), Point3D(-1, -1, -1), Point3D(-1, 0, 0) >>> r1, r2 = Ray3D(p1, p2), Ray3D(p1, p3) >>> r1.ydirection -oo >>> r2.ydirection 0 >>> r2.zdirection 0
See also
-
class
sympy.geometry.line.
Segment3D
[source]¶ A line segment in a 3D space.
- Parameters
p1 : Point3D
p2 : Point3D
Examples
>>> from sympy import Point3D >>> from sympy.geometry import Segment3D >>> Segment3D((1, 0, 0), (1, 1, 1)) # tuples are interpreted as pts Segment3D(Point3D(1, 0, 0), Point3D(1, 1, 1)) >>> s = Segment3D(Point3D(4, 3, 9), Point3D(1, 1, 7)); s Segment3D(Point3D(4, 3, 9), Point3D(1, 1, 7)) >>> s.points (Point3D(4, 3, 9), Point3D(1, 1, 7)) >>> s.length sqrt(17) >>> s.midpoint Point3D(5/2, 2, 8)
See also
Attributes
length
(number or sympy expression)
midpoint
(Point3D)