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: <9lalnl$cd3$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
I believe the documentation for RotationMatrix3D says it all.
1) Rotate by phi about z-axis
2) Rotate by theta about the new x-axis
3) Rotate by psi about the even newer z-axis
This is a rotation of the coordinate system, NOT the vector. To rotate the
vector instead you must reverse the order and signs of the angles. As far as
your problem goes, I am not sure about the statement. Are the three angles
the angles from the 3 axes of your new vector or ...?
Kevin
"ojg" <ole.jonny.gjoen at hitecvision.com> wrote in message
news:9lalnl$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
>
>
>