code: def _R_sqrt_mult(other, R_sqrt):
      """Do other @ R ** 0.5."""
      if R_sqrt.ndim == 1:
          assert other.shape[1] == R_sqrt.size
          out = R_sqrt * other
      else:
          assert R_sqrt.shape[1:3] == (3, 3)
          assert other.shape[1] == np.prod(R_sqrt.shape[:2])
          assert other.ndim == 2
          n_src = R_sqrt.shape[0]
          n_chan = other.shape[0]
          out = (
              np.matmul(
                  R_sqrt,
                  other.reshape(n_chan, n_src, 3).transpose(1, 2, 0),
              )
              .reshape(n_src * 3, n_chan)
              .T
          )
      return out
  
file_path: mne-python/mne/minimum_norm/_eloreta.py
imports: from functools import partial
  import numpy
  from ..defaults import _handle_default
  from ..fixes import _safe_svd
  from ..utils import eigh, logger, sqrtm_sym, warn
label_desc: Use image node_id 4 for calling a global function with example usage: _R_sqrt_mult(other, R_sqrt) and returns: out