No, not in the current framework. Even if there were, fwhm=.66 would not give you much smoothing. The intervertex distance is about 1mm, at fwhm=.66mm, the nearest vertex would be about 3 standard deviations away, meaning that the smoothing would be minimal.
On 12/21/18 12:12 PM, sha...@nmr.mgh.harvard.edu wrote: > So, is there anyway around this issue? > > >> The smoothing works through iterative nearest neighbor smoothing, so the >> fwhm is essentially discretized because you can't have fractions of an >> iteration. It looks like fwhm=0.66 is closer to 0 iterations than 1 >> iteration, so it chooses 0. >> >> On 12/21/18 11:23 AM, sha...@nmr.mgh.harvard.edu wrote: >>> Dear Surfers, >>> I am trying to use mris_fwhm to apply fwhm=0.66 to my fmri data >>> (voxel >>> size 1 mm iso)using the below command: >>> >>> mris_fwhm --s <SBJ_NAME>--hemi rh --smooth-only --i >>> fmcpr.sm0.self.projfrac_0.rh.nii.gz --fwhm 0.66 --o >>> fmcpr.sm0p66_surf.self.projfrac_0.rh.nii.gz --mask >>> /masks/brain.self.rh.nii.gz >>> >>> When I apply this command, it works without any error. The message on >>> screen is as below: >>> >>> <SBJ_NAME> rh white >>> Number of vertices 160391 >>> Number of faces 320778 >>> Total area 102725.085938 >>> GroupSurface 0 >>> AvgVtxArea 0.640467 >>> AvgVtxDist 0.875515 >>> StdVtxDist 0.253406 >>> Loading mask masks/brain.self.rh.nii.gz >>> Found 36045 voxels in mask >>> Not Polynomial detrending >>> Smoothing input by fwhm=0.660000, gstd=0.280276, niters=0 >>> Only smoothing, so saving and exiting now >>> >>> But the outcome is the same as input. I think it is expected based >>> on >>> (niters=0). When I use the same command with fwhm =1, then i see the >>> difference and niters=1. >>> >>> My question is, why is fwhm = 0.66 not acceptable? How can i solve this >>> issue. >>> >>> Regards >>> >>> _____________________________________ >>> >>> Shahin Nasr >>> >>> Assistant Prof. in Radiology >>> Harvard Medical School >>> Martinos Imaging Center, MGH >>> Bldg 149, 13th street, >>> Charlestown, MA 02129 >>> >>> _______________________________________________ >>> Freesurfer mailing list >>> Freesurfer@nmr.mgh.harvard.edu >>> https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer >> >> _______________________________________________ >> Freesurfer mailing list >> Freesurfer@nmr.mgh.harvard.edu >> https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer >> >> >> > > _____________________________________ > > Shahin Nasr > > Assistant Prof. in Radiology > Harvard Medical School > Martinos Imaging Center, MGH > Bldg 149, 13th street, > Charlestown, MA 02129 > > _______________________________________________ > Freesurfer mailing list > Freesurfer@nmr.mgh.harvard.edu > https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer _______________________________________________ Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer
