Hello
When we use to3d on our I files, we encounter the following unruliness:
We give it geometry we think is appropriate -i.e. identical to our functionals: a 75mm slab (which is oblique but we're letting it treat them as axial) but it tells us it knows better. see below.
We have fixed this by using 3dregrid to make the slice thickness be 5mm, but are confused about why this happens. Is the 3dregrid solution appropriate?

[alisona@benton T1]$ to3d -anat -prefix T1_new -xSLAB 218.281L-1.719L -ySLAB 218.281P-1.719P -zSLAB 2.5S-72.5S I*
to3d: 2D slices into 3D datasets for AFNI, by RW Cox
Counting images:  total=15 2D slices
Reading images: ...............
Using slice spacing=4.36446 instead of slice thickness=5
3D dataset written to disk

Thanks kindly!
Alison Adcock