frc::Rotation2d Class Reference

A rotation in a 2D coordinate frame represented by a point on the unit circle (cosine and sine). More...

#include <frc/geometry/Rotation2d.h>

Public Member Functions
constexpr	Rotation2d ()=default
	Constructs a Rotation2d with a default angle of 0 degrees.
constexpr	Rotation2d (units::angle_unit auto value)
	Constructs a Rotation2d with the given angle.
constexpr	Rotation2d (double x, double y)
	Constructs a Rotation2d with the given x and y (cosine and sine) components.
constexpr	Rotation2d (const Eigen::Matrix2d &rotationMatrix)
	Constructs a Rotation2d from a rotation matrix.
constexpr Rotation2d	operator+ (const Rotation2d &other) const
	Adds two rotations together, with the result being bounded between -π and π.
constexpr Rotation2d	operator- (const Rotation2d &other) const
	Subtracts the new rotation from the current rotation and returns the new rotation.
constexpr Rotation2d	operator- () const
	Takes the inverse of the current rotation.
constexpr Rotation2d	operator* (double scalar) const
	Multiplies the current rotation by a scalar.
constexpr Rotation2d	operator/ (double scalar) const
	Divides the current rotation by a scalar.
constexpr bool	operator== (const Rotation2d &other) const
	Checks equality between this Rotation2d and another object.
constexpr Rotation2d	RotateBy (const Rotation2d &other) const
	Adds the new rotation to the current rotation using a rotation matrix.
constexpr Eigen::Matrix2d	ToMatrix () const
	Returns matrix representation of this rotation.
constexpr units::radian_t	Radians () const
	Returns the radian value of the rotation.
constexpr units::degree_t	Degrees () const
	Returns the degree value of the rotation.
constexpr double	Cos () const
	Returns the cosine of the rotation.
constexpr double	Sin () const
	Returns the sine of the rotation.
constexpr double	Tan () const
	Returns the tangent of the rotation.

Detailed Description

A rotation in a 2D coordinate frame represented by a point on the unit circle (cosine and sine).

The angle is continuous, that is if a Rotation2d is constructed with 361 degrees, it will return 361 degrees. This allows algorithms that wouldn't want to see a discontinuity in the rotations as it sweeps past from 360 to 0 on the second time around.

Constructor & Destructor Documentation

Rotation2d() [1/4]

frc::Rotation2d::Rotation2d ( )

constexprdefault

Constructs a Rotation2d with a default angle of 0 degrees.

Rotation2d() [2/4]

frc::Rotation2d::Rotation2d ( units::angle_unit auto value )

inlineconstexpr

Constructs a Rotation2d with the given angle.

Parameters

value

The value of the angle.

Rotation2d() [3/4]

frc::Rotation2d::Rotation2d ( double x, double y )

inlineconstexpr

Constructs a Rotation2d with the given x and y (cosine and sine) components.

The x and y don't have to be normalized.

Parameters

x	The x component or cosine of the rotation.
y	The y component or sine of the rotation.

Rotation2d() [4/4]

frc::Rotation2d::Rotation2d ( const Eigen::Matrix2d & rotationMatrix )

inlineexplicitconstexpr

Constructs a Rotation2d from a rotation matrix.

Parameters

rotationMatrix

The rotation matrix.

Throws:

std::domain_error if the rotation matrix isn't special orthogonal.

Member Function Documentation

Cos()

double frc::Rotation2d::Cos ( ) const

inlineconstexpr

Returns the cosine of the rotation.

Returns

The cosine of the rotation.

Degrees()

units::degree_t frc::Rotation2d::Degrees ( ) const

inlineconstexpr

Returns the degree value of the rotation.

Returns

The degree value of the rotation.

See also

InputModulus to constrain the angle within (-180, 180]

operator*()

Rotation2d frc::Rotation2d::operator* ( double scalar ) const

inlineconstexpr

Multiplies the current rotation by a scalar.

Parameters

scalar

The scalar.

Returns

The new scaled Rotation2d.

operator+()

Rotation2d frc::Rotation2d::operator+ ( const Rotation2d & other ) const

inlineconstexpr

Adds two rotations together, with the result being bounded between -π and π.

For example, Rotation2d{30_deg} + Rotation2d{60_deg} equals Rotation2d{units::radian_t{std::numbers::pi/2.0}}

Parameters

other

The rotation to add.

Returns

The sum of the two rotations.

operator-() [1/2]

Rotation2d frc::Rotation2d::operator- ( ) const

inlineconstexpr

Takes the inverse of the current rotation.

This is simply the negative of the current angular value.

Returns

The inverse of the current rotation.

operator-() [2/2]

Rotation2d frc::Rotation2d::operator- ( const Rotation2d & other ) const

inlineconstexpr

Subtracts the new rotation from the current rotation and returns the new rotation.

For example, Rotation2d{10_deg} - Rotation2d{100_deg} equals Rotation2d{units::radian_t{-std::numbers::pi/2.0}}

Parameters

other

The rotation to subtract.

Returns

The difference between the two rotations.

operator/()

Rotation2d frc::Rotation2d::operator/ ( double scalar ) const

inlineconstexpr

Divides the current rotation by a scalar.

Parameters

scalar

The scalar.

Returns

The new scaled Rotation2d.

operator==()

bool frc::Rotation2d::operator== ( const Rotation2d & other ) const

inlineconstexpr

Checks equality between this Rotation2d and another object.

Parameters

other

The other object.

Returns

Whether the two objects are equal.

Radians()

units::radian_t frc::Rotation2d::Radians ( ) const

inlineconstexpr

Returns the radian value of the rotation.

Returns

The radian value of the rotation.

See also

AngleModulus to constrain the angle within (-π, π]

RotateBy()

Rotation2d frc::Rotation2d::RotateBy ( const Rotation2d & other ) const

inlineconstexpr

Adds the new rotation to the current rotation using a rotation matrix.

[cos_new]   [other.cos, -other.sin][cos]
[sin_new] = [other.sin,  other.cos][sin]
value_new = std::atan2(sin_new, cos_new)

Parameters

other

The rotation to rotate by.

Returns

The new rotated Rotation2d.

Sin()

double frc::Rotation2d::Sin ( ) const

inlineconstexpr

Returns the sine of the rotation.

Returns

The sine of the rotation.

Tan()

double frc::Rotation2d::Tan ( ) const

inlineconstexpr

Returns the tangent of the rotation.

Returns

The tangent of the rotation.

ToMatrix()

Eigen::Matrix2d frc::Rotation2d::ToMatrix ( ) const

inlineconstexpr

Returns matrix representation of this rotation.

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The documentation for this class was generated from the following file:

• frc/geometry/Rotation2d.h