Dear Henrik,
Henrik Walter wrote:
>
> Dear SPMler,
>
> when I estimate a model, Spm will create a xCon.mat file and beta
> images.
>
> When I compute contrasts, SPM generates ess*.img files for the
> f-contrasts and con*.img for the t-contrasts.
>
> The extension number of ess*.img and con*.img files equals the number of
> the contrast in the contrast manager.
>
> Now, if I later define a new Contrast manager which I copy in this
> directory the computation of contrasts will create new ess*.img files
> and new con*.img files.
>
> (By the way: There is now warning message which may cause problems if
> one has not controlled one's actual pwd)
>
> Now here ares the question: The beta-images do not change.
> Is that how the world should be?
> What do the beta-images tell me?
The beta-images are calculated in the estimation step and contain
the estimated beta-values for each voxel (-> image, parameter map)
each beta-image corresponds to one column in the design matrix.
They have to be recalculated only if the design matrix has changed.
Hope this helps,
Michael.
>
> TIA
>
> Henrik
>
> --
> Dr. Dr. Henrik Walter
> Abteilung Psychiatrie III
> Universitätsklinikum Ulm
> Leimgrubenweg 12
> 89075 Ulm
>
> fon: 0731/502 1489
> fax: 0731/502 1549
> e-mail: [log in to unmask]
--
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Dr. Michael Erb
Sektion f. experimentelle Kernspinresonanz des ZNS
Abteilung Neuroradiologie
Universitaetsklinikum
Hoppe-Seyler_Str. 3, D-72076 Tuebingen
Tel.: +49(0)7071/2985398 priv. +49(0)7071/61559
Fax.: +49(0)7071/294371
e-mail: <[log in to unmask]>
www: http://www.medizin.uni-tuebingen.de/nrad/sektion
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