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help > RE: Voxel-to-Voxel analysis
Aug 29, 2015 05:08 AM | Alfonso Nieto-Castanon - Boston University
RE: Voxel-to-Voxel analysis
Hi Annie,
Yes, the files PCAcov_Measure*_Component{N}.nii in the conn*/results/firstlevel/ folder contain the cumulative percentage variance (note: scaled between 0 and 1, instead of between 0 and 100) explained by the first N components for each voxel (e.g. the file PCAcov_Measure*_Component003.nii contains the percentage variance explained by the first three components)
Best
Alfonso
Originally posted by Annie Möller:
Yes, the files PCAcov_Measure*_Component{N}.nii in the conn*/results/firstlevel/ folder contain the cumulative percentage variance (note: scaled between 0 and 1, instead of between 0 and 100) explained by the first N components for each voxel (e.g. the file PCAcov_Measure*_Component003.nii contains the percentage variance explained by the first three components)
Best
Alfonso
Originally posted by Annie Möller:
Hi Alfonso!
I am making a lot of progress with my analysis and I think I am starting to get a grasp of how to use the contrasts and barplots and also comparing these means in the Calculator in Tools.
Again, Big Thanks for taking the time to answer people like me...
Now, me and my colleagues are trying to evaluate if 5 was an optimal number of components to choose. We have 25 subjects, so it might be better with 3 or 4 components, according to your rule of thumb.
Is there a way to see how much variance is explained by each component now when we have 5? This value must be calculated on the way I guess, but is it stored somewhere?
Best regards
/Annie
I am making a lot of progress with my analysis and I think I am starting to get a grasp of how to use the contrasts and barplots and also comparing these means in the Calculator in Tools.
Again, Big Thanks for taking the time to answer people like me...
Now, me and my colleagues are trying to evaluate if 5 was an optimal number of components to choose. We have 25 subjects, so it might be better with 3 or 4 components, according to your rule of thumb.
Is there a way to see how much variance is explained by each component now when we have 5? This value must be calculated on the way I guess, but is it stored somewhere?
Best regards
/Annie
Threaded View
| Title | Author | Date |
|---|---|---|
| Annie Möller | Aug 20, 2015 | |
| Alfonso Nieto-Castanon | Aug 21, 2015 | |
| Annie Möller | Aug 24, 2015 | |
| Alfonso Nieto-Castanon | Aug 24, 2015 | |
| Annie Möller | Aug 28, 2015 | |
| Alfonso Nieto-Castanon | Aug 29, 2015 | |
| Annie Möller | Sep 1, 2015 | |