'Compute the Neuromag dev_head_t from matched points.'

def compute_dev_head_t(self):

    from ..coreg import fit_matched_points
    if ((self.elp is None) or (self.hpi is None)):
        raise RuntimeError('must    have    both    elp    and    hpi    to    compute    the    device    to    head    transform')
    self.dev_head_t = fit_matched_points(tgt_pts=self.elp, src_pts=self.hpi, out='trans')
