org.apache.commons.math3.geometry.euclidean.threed

## Enum RotationConvention

• ### Enum Constant Summary

Enum Constants
Enum Constant and Description
FRAME_TRANSFORM
Constant for rotation that have the semantics of a frame conversion.
VECTOR_OPERATOR
Constant for rotation that have the semantics of a vector operator.
• ### Method Summary

Methods
Modifier and Type Method and Description
static RotationConvention valueOf(String name)
Returns the enum constant of this type with the specified name.
static RotationConvention[] values()
Returns an array containing the constants of this enum type, in the order they are declared.
• ### Methods inherited from class java.lang.Enum

clone, compareTo, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf
• ### Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait
• ### Enum Constant Detail

• #### VECTOR_OPERATOR

public static final RotationConvention VECTOR_OPERATOR
Constant for rotation that have the semantics of a vector operator.

According to this convention, the rotation moves vectors with respect to a fixed reference frame.

This means that if we define rotation r is a 90 degrees rotation around the Z axis, the image of vector Vector3D.PLUS_I would be Vector3D.PLUS_J, the image of vector Vector3D.PLUS_J would be Vector3D.MINUS_I, the image of vector Vector3D.PLUS_K would be Vector3D.PLUS_K, and the image of vector with coordinates (1, 2, 3) would be vector (-2, 1, 3). This means that the vector rotates counterclockwise.

This convention was the only one supported by Apache Commons Math up to version 3.5.

The difference with FRAME_TRANSFORM is only the semantics of the sign of the angle. It is always possible to create or use a rotation using either convention to really represent a rotation that would have been best created or used with the other convention, by changing accordingly the sign of the rotation angle. This is how things were done up to version 3.5.

• #### FRAME_TRANSFORM

public static final RotationConvention FRAME_TRANSFORM
Constant for rotation that have the semantics of a frame conversion.

According to this convention, the rotation considered vectors to be fixed, but their coordinates change as they are converted from an initial frame to a destination frame rotated with respect to the initial frame.

This means that if we define rotation r is a 90 degrees rotation around the Z axis, the image of vector Vector3D.PLUS_I would be Vector3D.MINUS_J, the image of vector Vector3D.PLUS_J would be Vector3D.PLUS_I, the image of vector Vector3D.PLUS_K would be Vector3D.PLUS_K, and the image of vector with coordinates (1, 2, 3) would be vector (2, -1, 3). This means that the coordinates of the vector rotates clockwise, because they are expressed with respect to a destination frame that is rotated counterclockwise.

The difference with VECTOR_OPERATOR is only the semantics of the sign of the angle. It is always possible to create or use a rotation using either convention to really represent a rotation that would have been best created or used with the other convention, by changing accordingly the sign of the rotation angle. This is how things were done up to version 3.5.

• ### Method Detail

• #### values

public static RotationConvention[] values()
Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows:
for (RotationConvention c : RotationConvention.values())
System.out.println(c);

Returns:
an array containing the constants of this enum type, in the order they are declared
• #### valueOf

public static RotationConvention valueOf(String name)
Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)
Parameters:
name - the name of the enum constant to be returned.
Returns:
the enum constant with the specified name
Throws:
IllegalArgumentException - if this enum type has no constant with the specified name
NullPointerException - if the argument is null