#4 The size of voxel betas and voxel coordinates do not match

[Ceyda Sayali]

Hi,

I am trying to extract the beta values of all voxels in a beta image while using an ROI as my mask. Consequently, I would like to match these beta values to their corresponding voxel coordinates, so I can learn both the beta value and the coordinate of each voxel.

I used the function [Y multv vXYZ mat]=getdata(roi.nii,betaimage). However the lengths of the Y values and the vXYZ do not match. It appears that there are more voxel coordinates than the number of extracted beta values. The dimension and the voxel size of my roi and betaimage are identical, so it's not clear why there should be a discrepancy.

Is there a better way of obtaining this information?

Thank you!

[Matthew Brett]

Hi,

On Wed, Aug 24, 2016 at 4:01 PM, Ceyda Sayali zceydas@users.sf.net wrote:

---

[support-requests:#4] The size of voxel betas and voxel coordinates do not
match

Status: open
Group: v1.0 (example)
Created: Wed Aug 24, 2016 11:01 PM UTC by Ceyda Sayali
Last Updated: Wed Aug 24, 2016 11:01 PM UTC
Owner: nobody

Hi,

I am trying to extract the beta values of all voxels in a beta image while
using an ROI as my mask. Consequently, I would like to match these beta
values to their corresponding voxel coordinates, so I can learn both the
beta value and the coordinate of each voxel.

I used the function [Y multv vXYZ mat]=getdata(roi.nii,betaimage). However
the lengths of the Y values and the vXYZ do not match. It appears that there
are more voxel coordinates than the number of extracted beta values. The
dimension and the voxel size of my roi and betaimage are identical, so it's
not clear why there should be a discrepancy.

Is there a better way of obtaining this information?

Hum - I don't often use that function on a single image.

So, I think I'm expecting these sizes, where V is the number of voxels:

Y : 1 by V
multv : 1 by V (or V by 1)
vXYZ : 1 by V

Is that not what you get?

Best,

Matthew

[Ceyda Sayali]

There is a discrepancy between the sizes of Y, multv and vXYZ in my case:

Y: 1 by 8601
mulv: 1 by 8601
vXYZ: 3 by 11435