Orientation classes

An vector of orientations, each represented by a vector of numbers. Each of these types stores orientations as rows of a matrix in slot x.

The eulerzyx class uses 3 Euler angles in the roll-pitch-yaw scheme (rotation about Z axis, then Y axis, then X axis).

The eulerzxz class uses 3 Euler angles in the X system scheme (rotation about Z axis, then X axis, then Z axis again).

The rotvector class uses the 9 components of a 3 x 3 rotation matrix, stored in column-major order.

The quaternion class uses the 4 components of a unit quaternion.

The skewvector class uses the 3 non-zero components of a skew-symmetric matrix, where (x,y,z) stores the matrix ((0, -z, y), (z, 0, -x), (-y, x, 0)).

Objects from the Class

Objects of each class can be created by calls to the corresponding constructor functions: eulerzyx, eulerzxz, rotvector, quaternion, skewmatrix and skewvector.

Slots

x:: An n x m matrix object holding the vector representations, where m is 3, 4, or 9.

Extends

Class "orientation", directly. Class "vector", by class "orientation".

Methods

[, [<-: Extract or assign to subvector
[[, [[<-: Extract or assign to an entry
length: The length of the orientation vector
coerce: Coerce methods are defined to convert all orientation descendants from one to another, and to coerce an appropriately shaped matrix or array to a rotmatrix

Author

Duncan Murdoch

Examples

x <- eulerzyx(0,pi/4,0)
x
#> An object of class "eulerzyx"
#> Slot "x":
#>      psi     theta phi
#> [1,]   0 0.7853982   0
#> 
eulerzxz(x)
#> An object of class "eulerzxz"
#> Slot "x":
#>           phi     theta       psi
#> [1,] 1.570796 0.7853982 -1.570796
#> 
rotmatrix(x)
#> An object of class "rotmatrix"
#> Slot "x":
#> , , 1
#> 
#>           [,1] [,2]       [,3]
#> [1,] 0.7071068    0 -0.7071068
#> [2,] 0.0000000    1  0.0000000
#> [3,] 0.7071068    0  0.7071068
#> 
#> 
rotvector(x)
#> An object of class "rotvector"
#> Slot "x":
#>           [,1] [,2]      [,3] [,4] [,5] [,6]       [,7] [,8]      [,9]
#> [1,] 0.7071068    0 0.7071068    0    1    0 -0.7071068    0 0.7071068
#> 
quaternion(x)
#> An object of class "quaternion"
#> Slot "x":
#>      q1        q2 q3        q4
#> [1,]  0 0.3826834  0 0.9238795
#> 
skewvector(x)
#> An object of class "skewvector"
#> Slot "x":
#>      [,1]      [,2] [,3]
#> [1,]    0 0.7853982    0
#>