You are right, I was too sloppy.
It has to be:
XYZ(:,sub2ind(size(Img),10,20, 6))
Cheers,
Michael
Am 15.10.2013 12:15, schrieb Tibor Auer:
> This may not be correct. Especially, because XYZ is not a 3D matrix,
> but a 3 x nVox matrix containing the XYZ coords for the voxels with the
> given "index".
> Let's assume that we have an nX x nY x nZ image (img) so the XYZ is a 3
> x (nX*nY*nZ) matrix; and we want the "index" for the voxel at X,Y,Z.
> There are two options to figure out the "index":
> /i//nd = (Z-1)*(nX*nY)//+(Y-1)*nX+X;//% specific/
> or
> /ind = 1://length(XYZ); ind = reshape(ind,size(img));//ind = ind(X,Y,Z);
> % general/
> and
> /XYZ(:,ind) /
> gives you the coordinates
> Cheers,
> Auer, Tibor M.D. Ph.D.
> MRC Cognition and Brain Sciences Unit
> 15 Chaucer Road
> Cambridge
> CB2 7EF
> United Kingdom
> Phone/Work: +44-(0)1223-355294 (ext. 869)
> Mail: [log in to unmask]
> -----Original Message-----
> From: SPM (Statistical Parametric Mapping) [mailto:[log in to unmask]]
> On Behalf Of Michael Erb
> Sent: Monday, October 14, 2013 10:00 PM
> To: [log in to unmask]
> Subject: Re: [SPM] Q) How to figure out the MNI coordinate of matrix x,y,z?
> try:
> [Img, XYZ]=spm_read_vols(Vol);
> XYZ(10,20, 6) will give you the MNI coordinate in mm
> How do I know that?
> >> help spm_read_vols
> Read in entire image volumes
> FORMAT [Y,XYZ] = spm_read_vols(V,mask)
> V - vector of mapped image volumes to read in (from spm_vol)
> mask - implicit zero mask?
> Y - 4D matrix of image data, fourth dimension indexes images
> XYZ - 3xn matrix of XYZ locations returned (in mm)
>
> __________________________________________________________________________
> For image data types without a representation of NaN (see spm_type),
> implicit zero masking can be used. If mask is set, then zeros are
> treated as masked, and returned as NaN.
>
> __________________________________________________________________________
> Copyright (C) 2008 Wellcome Trust Centre for Neuroimaging
> Hope that helps,
> Michael
> Am 14.10.2013 22:10, schrieb Glen Lee:
>> Hello SPM experts,
>>
>> I'd like to figure out the MNI coordinate that corresponds to matlab's
>> matrix of an image.
>> For example, I'd like to know what the MNI x,y,z that corresponds to
>> 10,20,6 in matrix below.
>>
>> Vol=spm_vol('tmap.nii');
>> Img=spm_read_vols(Vol);
>>
>> Img(10,20, 6)-> MNI??
>>
>>
>> thanks in advance,
>> Glen
> --
> <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
> Dr. Michael Erb
> Department of Biomedical Magnetic Resonance University of Tübingen
> Hoppe-Seyler-Str. 3
> 72076 Tübingen, Germany
> Tel.: +49(0)7071/2987753 priv. +49(0)7071/61559
> Fax.: +49(0)7071/294371
> e-mail: <[log in to unmask]
> <mailto:[log in to unmask]>>
> www:
> http://www.medizin.uni-tuebingen.de/Forschung/Kliniken/Radiologie/Biomedizinische+Magnetresonanz.html
> <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
--
<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
Dr. Michael Erb
Department of Biomedical Magnetic Resonance
University of Tübingen
Hoppe-Seyler-Str. 3
72076 Tübingen, Germany
Tel.: +49(0)7071/2987753 priv. +49(0)7071/61559
Fax.: +49(0)7071/294371
e-mail: <[log in to unmask]>
www:
http://www.medizin.uni-tuebingen.de/Forschung/Kliniken/Radiologie/Biomedizinische+Magnetresonanz.html
<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
