Dear Eugenia,
If you have two within-subject factors with three levels each, the
F-contrasts for main effects and interaction of this two-way ANOVA are
given by:
c = spm_make_contrasts([3 3]);
These documents will give you more details about how to specify the
design matrices:
https://en.wikibooks.org/wiki/SPM/Group_Analysis
https://psyarxiv.com/a5469
Their examples are for a 2x3x2 ANOVA but the principles are the same -
let us know if it's unclear.
Best regards,
Guillaume.
On 26/11/2018 07:23, eugenia flipakopoulou wrote:
> Dear experts,
>
> I would like to ask which is the best way to perform a 3x3 ANOVA in
> SPM?I have 3 variables with 3 levels each and I am interestedn in the
> main effects and the interaction.How should I create the
> contrasts?Manually in the first level analysis or choose factorial from
> the first level?I am sorry for the simplicity of th question but the spm
> manual does not provide enough info how to use the SPM menu for this
> step by step.Thanl you in advance!
>
> Best regards,
>
> E.F.
--
Guillaume Flandin, PhD
Wellcome Centre for Human Neuroimaging
UCL Queen Square Institute of Neurology
London WC1N 3BG
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