frc.team670.robot.utils.math

Class Rotation

java.lang.Object

frc.team670.robot.utils.math.Rotation

public class Rotation
extends java.lang.Object

Constructor Summary

Constructors

Constructor and Description
Rotation() Default constructor: rotation matrix of angle 0
Rotation(double cos, double sin)
Rotation(double cos, double sin, boolean normalize) Create a rotation matrix from the sin and cos of the angle.
Rotation(Translation directionVector) Create a rotation matrix from a translation vector.

Method Summary

Modifier and Type	Method and Description
double	cos()
double	degrees()
static Rotation	fromDegrees(double degrees)
static Rotation	fromRadians(double radians)
Rotation	inverse() Calculates the inverse of this rotation matrix Basically what when multiplied after this matrix will turn it into the identity matrix In other words, it's the rotation matrix representing the angle that is the opposite of this angle
Rotation	normal() Calculates the Normal or perpendicular rotation matrix to the angle of this rotation matrix Example: If this represents a rotation matrix of 0 degrees, normal will return a rotation matrix for 90 degrees
double	radians() Returns between -pi and pi
Rotation	rotate(Rotation other) Rotates this rotation matrix by a specified angle
double	sin()
double	tan()
java.lang.String	toString()

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

Rotation

public Rotation(double cos,
                double sin,
                boolean normalize)

Create a rotation matrix from the sin and cos of the angle.

Parameters:

cos - cos of the angle of the rotation

sin - sin of the angle of the rotation

normalize - whether or not we should "normalize" this rotation normalize()

Rotation

public Rotation(double cos,
                double sin)

Rotation

public Rotation()

Default constructor: rotation matrix of angle 0

Rotation

public Rotation(Translation directionVector)

Create a rotation matrix from a translation vector. This basically is the angle from the positive x axis to the translation vector.

Parameters:

directionVector - the translation vector to calculate the angle from

Method Detail

fromRadians

public static Rotation fromRadians(double radians)

fromDegrees

public static Rotation fromDegrees(double degrees)

cos

public double cos()

sin

public double sin()

tan

public double tan()

radians

public double radians()

Returns between -pi and pi

Returns:

The angle in radians

degrees

public double degrees()

normal

public Rotation normal()

Calculates the Normal or perpendicular rotation matrix to the angle of this rotation matrix Example: If this represents a rotation matrix of 0 degrees, normal will return a rotation matrix for 90 degrees

Returns:

The normal rotation matrix to this rotation matrix

rotate

public Rotation rotate(Rotation other)

Rotates this rotation matrix by a specified angle

Basically multiplies the specified rotation matrix after this rotation matrix

[[cos', -sin'] = [[cos_0, -sin_0] * [[cos_1, -sin_1] = [[cos_0*cos_1+(-sin_0)*sin_1, cos_0*(-sin_1)+(-sin_0)*cos_1] [sin', cos']] [sin_0, cos_0]] [sin_1, cos_1]] [sin_0*cos_1+cos_0*sin_1, sin_0*(-sin_1)+cos_0*cos_1 ]] So for implementation purposes, basically: cos' = cos_0*cos_1+(-sin_0)*sin_1 sin' = sin_0*cos_1+cos_0*sin_1

Parameters:

other - Angle to rotate this rotation matrix by

Returns:

Rotated rotation matrix

inverse

public Rotation inverse()

Calculates the inverse of this rotation matrix Basically what when multiplied after this matrix will turn it into the identity matrix In other words, it's the rotation matrix representing the angle that is the opposite of this angle

Since rotation matrices are orthagonal matrices, the inverse is the same as the transpose Calculating the transpose is much cheaper than calculating the inverse

[[cos, -sin]T = [[cos, sin] [sin, cos]] [-sin, cos]]

For implementation purposes, cos' = cos sin' = -sin

Returns:

Inverse of this rotation matrix

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object