15.5.504 rm2v

rm2v(r)

[SOFA] Returns the rotation vector corresponding to rotation matrix r, which must have 3 elements in its first two dimensions. The returned rotation vector has the same direction as the Euler axis of matrix r and has its magnitude equal to the rotation angle in radians of the rotation matrix. It has the same dimensions as r except that the first dimension (equal to 3) is omitted.