"xifti" objectsConcatenate "xifti" objects along the columns. They must have the same
brainstructures. The first "xifti"'s metadata will be retained, including
its intent.
merge_xifti(..., xifti_list = NULL)Provide as arguments the "xifti" objects to
concatenate, OR the single argument xifti_list which should be a
list of "xifti" objects. (If xifti_list is provided all other
inputs will be ignored.)
The concatenated "xifti" object.