Hello,
Can you tar and upload your input files to:
http://www.fmrib.ox.ac.uk/cgi-bin/upload.cgi
and let us know the 6-digit reference number and the command line call used?
Many Regards
Matthew
> Hello,
>
> I know there are many posts covering this topic already but I can't find any that solves my problem:
>
> I have a 2-way anova design: one factor (group) with 2 levels and one factor (genotype) with 3 levels. To save time I'm testing interactions and main effects separately, so I can run them at the same time (just checking - i hope this is ok). I'm testing for 6 interactions, and when testing these normally it all seems fine. The problem occurs when I'm trying to add an F-test for all interactions together.
>
> I get the "singular matrix" error as attached below this email (reported by other people as well).
>
> I suspect this has something to do with my design files, particularly the .fts matrix. So here we go:
>
> My .mat file (assuming 1 subject per genotypeXgroup cell):
>
> /NumWaves 6
> /NumPoints 177
> /PPheights
> /Matrix
> 1 0 0 0 0 0 (group1 genotype1)
> 0 1 0 0 0 0 (group2 genotype1)
> 0 0 1 0 0 0 (group1 genotype2)
> 0 0 0 1 0 0 (group2 genotype2)
> 0 0 0 0 1 0 (group 1 genotype3)
> 0 0 0 0 0 1 (group2 genotype3)
>
>
> My .con file
>
> /NumWaves 6
> /NumContrasts 6
> /PPheights
> /Matrix
> 2 -2 -1 1 -1 1
> -2 2 1 -1 1 -1
> 1 -1 1 -1 -2 2
> -1 1 -1 1 2 -2
> 1 -1 0 0 -1 1
> -1 1 0 0 1 -1
>
>
> My .fst file
>
> /NumWaves 6
> /NumContrasts 1
> /Matrix
> 1 1 1 1 1 1
>
>
> Apologies for this long explanation! At least I hope it's kind of clear...
>
> Thanks,
>
> Emma
>
>
>
>
>
> --------------------------------------------------------------------------------
> Data loaded
> ERROR: Program failed
>
> An exception has been thrown
> Runtime error:- detected by Newmat: matrix is singular
>
> MatrixType = Crout # Rows = 6; # Cols = 6
> Trace: Crout(lubksb); GeneralSolvI; InvertedMatrix::Evaluate.
>
>
> Exiting
> ----------------------------------------------------------------------------------
>
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