Hi,
The transformation matrix in FSL is composed as:
mat = rotation * skew * scale
Note that the translation and rotation are put
together in the same matrix and not separated out,
since the centre of rotation and the translation are
intrinsically linked.
For the scale and skew matrices, your
format is correct.
All the best,
Mark
On 8 Jun 2009, at 11:19, Kenji wrote:
> Dear FSL experts
>
> As for the data.ecclog(eddy_current) results,
> I know if I use avscale –allparams, I get Rotation&Translation Matrix.
> But, I have not understood the calculation ( in miscmaths.cc) well
> yet.
>
> the data.ecclog result is
> 0.998188 -0.000096 0.003312 0.467322
> 0.001160 1.000481 -0.000204 0.324068
> -0.003291 0.003232 1.013932 -1.214359
> 0.000000 0.000000 0.000000 1.000000.
>
> Is this Matrix a numerical result of
> <Rotation*Translation*Skew*Scale >?
> i.e. Is this order <R*T*Sk*Sc> correct?
> and is the arrangement of the variable below correct?
>
> T Skew Scale
> 1 0 0 Tx 1 ax by 0 Sx 0 0 0
> 0 1 0 Ty 0 1 cz 0 0 Sy 0 0
> 0 0 1 Tz 0 0 1 0 0 0 Sz 0
> 0 0 0 1 0 0 0 1 0 0 0 1
>
> Thanks
> Kenji
>
|