# Class FieldLine<T extends CalculusFieldElement<T>>

java.lang.Object
org.hipparchus.geometry.euclidean.threed.FieldLine<T>
Type Parameters:
T - the type of the field elements

public class FieldLine<T extends CalculusFieldElement<T>> extends Object
The class represent lines in a three dimensional space.

Each oriented line is intrinsically associated with an abscissa which is a coordinate on the line. The point at abscissa 0 is the orthogonal projection of the origin on the line, another equivalent way to express this is to say that it is the point of the line which is closest to the origin. Abscissa increases in the line direction.

• ## Constructor Summary

Constructors
Constructor
Description
FieldLine(FieldLine<T> line)
Copy constructor.
FieldLine(FieldVector3D<T> p1, FieldVector3D<T> p2, double tolerance)
Build a line from two points.
• ## Method Summary

Modifier and Type
Method
Description
FieldVector3D<T>
closestPoint(FieldLine<T> line)
Compute the point of the instance closest to another line.
boolean
contains(FieldVector3D<T> p)
Check if the instance contains a point.
boolean
contains(Vector3D p)
Check if the instance contains a point.
T
distance(FieldLine<T> line)
Compute the shortest distance between the instance and another line.
T
distance(FieldVector3D<T> p)
Compute the distance between the instance and a point.
T
distance(Vector3D p)
Compute the distance between the instance and a point.
T
getAbscissa(FieldVector3D<T> point)
Get the abscissa of a point with respect to the line.
T
getAbscissa(Vector3D point)
Get the abscissa of a point with respect to the line.
FieldVector3D<T>
getDirection()
Get the normalized direction vector.
FieldVector3D<T>
getOrigin()
Get the line point closest to the origin.
double
getTolerance()
Get the tolerance below which points are considered identical.
FieldVector3D<T>
intersection(FieldLine<T> line)
Get the intersection point of the instance and another line.
boolean
isSimilarTo(FieldLine<T> line)
Check if the instance is similar to another line.
FieldVector3D<T>
pointAt(double abscissa)
Get one point from the line.
FieldVector3D<T>
pointAt(T abscissa)
Get one point from the line.
void
reset(FieldVector3D<T> p1, FieldVector3D<T> p2)
Reset the instance as if built from two points.
FieldLine<T>
revert()
Get a line with reversed direction.

### Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
• ## Constructor Details

• ### FieldLine

public FieldLine(FieldVector3D<T> p1, FieldVector3D<T> p2, double tolerance) throws MathIllegalArgumentException
Build a line from two points.
Parameters:
p1 - first point belonging to the line (this can be any point)
p2 - second point belonging to the line (this can be any point, different from p1)
tolerance - tolerance below which points are considered identical
Throws:
MathIllegalArgumentException - if the points are equal
• ### FieldLine

public FieldLine(FieldLine<T> line)
Copy constructor.

The created instance is completely independent from the original instance, it is a deep copy.

Parameters:
line - line to copy
• ## Method Details

• ### reset

public void reset(FieldVector3D<T> p1, FieldVector3D<T> p2) throws MathIllegalArgumentException
Reset the instance as if built from two points.
Parameters:
p1 - first point belonging to the line (this can be any point)
p2 - second point belonging to the line (this can be any point, different from p1)
Throws:
MathIllegalArgumentException - if the points are equal
• ### getTolerance

public double getTolerance()
Get the tolerance below which points are considered identical.
Returns:
tolerance below which points are considered identical
• ### revert

public  revert()
Get a line with reversed direction.
Returns:
a new instance, with reversed direction
• ### getDirection

public  getDirection()
Get the normalized direction vector.
Returns:
normalized direction vector
• ### getOrigin

public  getOrigin()
Get the line point closest to the origin.
Returns:
line point closest to the origin
• ### getAbscissa

public T getAbscissa(FieldVector3D<T> point)
Get the abscissa of a point with respect to the line.

The abscissa is 0 if the projection of the point and the projection of the frame origin on the line are the same point.

Parameters:
point - point to check
Returns:
abscissa of the point
• ### getAbscissa

public T getAbscissa(Vector3D point)
Get the abscissa of a point with respect to the line.

The abscissa is 0 if the projection of the point and the projection of the frame origin on the line are the same point.

Parameters:
point - point to check
Returns:
abscissa of the point
• ### pointAt

public  pointAt(T abscissa)
Get one point from the line.
Parameters:
abscissa - desired abscissa for the point
Returns:
one point belonging to the line, at specified abscissa
• ### pointAt

public  pointAt(double abscissa)
Get one point from the line.
Parameters:
abscissa - desired abscissa for the point
Returns:
one point belonging to the line, at specified abscissa
• ### isSimilarTo

public boolean isSimilarTo(FieldLine<T> line)
Check if the instance is similar to another line.

Lines are considered similar if they contain the same points. This does not mean they are equal since they can have opposite directions.

Parameters:
line - line to which instance should be compared
Returns:
true if the lines are similar
• ### contains

public boolean contains(FieldVector3D<T> p)
Check if the instance contains a point.
Parameters:
p - point to check
Returns:
true if p belongs to the line
• ### contains

public boolean contains(Vector3D p)
Check if the instance contains a point.
Parameters:
p - point to check
Returns:
true if p belongs to the line
• ### distance

public T distance(FieldVector3D<T> p)
Compute the distance between the instance and a point.
Parameters:
p - to check
Returns:
distance between the instance and the point
• ### distance

public T distance(Vector3D p)
Compute the distance between the instance and a point.
Parameters:
p - to check
Returns:
distance between the instance and the point
• ### distance

public T distance(FieldLine<T> line)
Compute the shortest distance between the instance and another line.
Parameters:
line - line to check against the instance
Returns:
shortest distance between the instance and the line
• ### closestPoint

public  closestPoint(FieldLine<T> line)
Compute the point of the instance closest to another line.
Parameters:
line - line to check against the instance
Returns:
point of the instance closest to another line
• ### intersection

public  intersection(FieldLine<T> line)
Get the intersection point of the instance and another line.
Parameters:
line - other line
Returns:
intersection point of the instance and the other line or null if there are no intersection points