Re: Rotation3D, MatrixRotation3D ?
- To: mathgroup at smc.vnet.net
- Subject: [mg30401] Re: Rotation3D, MatrixRotation3D ?
- From: "Kevin J. McCann" <kevinmccann at Home.com>
- Date: Wed, 15 Aug 2001 01:04:07 -0400 (EDT)
- References: <email@example.com>
- Sender: owner-wri-mathgroup at wolfram.com
I believe the documentation for RotationMatrix3D says it all. 1) Rotate by phi about z-axis 2) Rotate by theta about the new x-axis 3) Rotate by psi about the even newer z-axis This is a rotation of the coordinate system, NOT the vector. To rotate the vector instead you must reverse the order and signs of the angles. As far as your problem goes, I am not sure about the statement. Are the three angles the angles from the 3 axes of your new vector or ...? Kevin "ojg" <ole.jonny.gjoen at hitecvision.com> wrote in message news:9lalnl$cd3$1 at smc.vnet.net... > Question regarding rotations. > > Some of the documentation found regarding this is not as far as I can see > complete in the documentation, at least the subject is difficult enough to > make me unsure once not 100% clear:) > > Fist, what are the defined "euler angles" in mathematica, and in what order > are they applied? > > Second, of which side of the vector is the rotational matrix multiplied ? > > Third, is there a mathematica way to rotate around an abitrary rotational > axis? If not, what would the mathematica matix be for this? > > My problem to solve is as follows: Given three rotational angles (a,b,c) > applied in order to the following three rotational axes: Y axis, X axis, Z > axis. (usual right hand system). This rotation applied to any vector v will > give you a vector V (first Y rotation applied on v, etc). > > > Now, given a rotational matrix with pure numerical values in, I need to find > the three angles, and I need a general formulae for this solution taking > care of the special cases. > > Thanks, > Johnny > > >