steve,
why does randomise output a t-stat and not a z-stat? if we were to convert
these to z-stats, what would be the appropriate dof if we were doing a
paired t-test type analysis with 2 groups of 15 scans each? dof=28? or for
randomise, is dof calculated differently?
thanks
vitaly
> Both options take the same kind of argument; it is the cluster-
> forming threshold and is in the units of the raw t-statistic image
> formed by randomise. So for example if you enter 2.5 then clusters
> above t=2.5 will be formed and tested for significance on the basis
> of their extent (-c option) or "mass (-C option).
>
> Cheers.
>
>
>
> On 30 Mar 2007, at 20:26, Polly Dhond wrote:
>
>> Hi,
>>
>> Can you please tell me the format(s) of the input for the -c and
>> -C flags in randomize are? i.e. example value. Thanks.
>>
>> Regards
>> Polly
>>
>>
>>
>> --
>> Rupali P. Dhond, Ph.D.
>> Dept. of Radiology, MGH
>> Martinos Center for Biomedical Imaging
>> Rm 2301, Bldg 149, 13th Street
>> Charlestown, MA 02129
>> e-mail: [log in to unmask]
>
>
> ------------------------------------------------------------------------
> ---
> Stephen M. Smith, Professor of Biomedical Engineering
> Associate Director, Oxford University FMRIB Centre
>
> FMRIB, JR Hospital, Headington, Oxford OX3 9DU, UK
> +44 (0) 1865 222726 (fax 222717)
> [log in to unmask] http://www.fmrib.ox.ac.uk/~steve
> ------------------------------------------------------------------------
> ---
>
>
>
|`~~~~~~~~~~~~~\|/~~~~~~~~~~~~~'|
Vitaly Napadow, Ph.D., Lic.Ac.
Dept. of Radiology
Massachusetts General Hospital
CNY 149-2301, 13th St.
Charlestown, MA 02129
phone: (617) 724-3402
fax: (617) 726-7422
email: [log in to unmask]
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