class_docstr: Class for the Siegel metric.
class_docstr_tok: ["Class","for","the","Siegel","metric","."]
docstr: Compute the Siegel logarithm map at zero.
  
  Compute the logarithm map at zero (null matrix) of point.
  
  Parameters
  ----------
  point : array-like, shape=[..., n, n]
      Point on the Siegel space.
  
  Returns
  -------
  log_at_zero : array-like, shape=[..., n, n]
      Riemannian logarithm at zero (null matrix).
docstr_tok: ["Compute","the","Siegel","logarithm","map","at","zero",".","Compute","the","logarithm","map","at","zero","(","null","matrix",")","of","point",".","Parameters","--","--","--","--","--","point",":","array-like",",","shape=","[","...",",","n",",","n","]","Point","on","the","Siegel","space",".","Returns","--","--","--","-","log_at_zero",":","array-like",",","shape=","[","...",",","n",",","n","]","Riemannian","logarithm","at","zero","(","null","matrix",")","."]
code: def log_at_zero(point):
      """Compute the Siegel logarithm map at zero.
  
      Compute the logarithm map at zero (null matrix) of point.
  
      Parameters
      ----------
      point : array-like, shape=[..., n, n]
          Point on the Siegel space.
  
      Returns
      -------
      log_at_zero : array-like, shape=[..., n, n]
          Riemannian logarithm at zero (null matrix).
      """
      identity = _create_identity_mat(point.shape, dtype=point.dtype)
      point_transconj = ComplexMatrices.transconjugate(point)
      aux_1 = gs.matmul(point, point_transconj)
      aux_2 = powermh(aux_1, 1 / 2)
      num = identity + aux_2
      den = identity - aux_2
      inv_den = powermh(den, -1)
      frac = gs.matmul(num, inv_den)
      factor_1 = gs.linalg.logm(frac)
      factor_2 = powermh(aux_2, -1)
      factor_2 = gs.where(
          gs.isnan(factor_2), gs.zeros_like(factor_2), factor_2
      )
      prod_1 = gs.matmul(factor_1, factor_2)
      return gs.matmul(prod_1, point) * 0.5
  
imports: import geomstats.backend
  from geomstats.geometry.base import ComplexVectorSpaceOpenSet
  from geomstats.geometry.complex_matrices import ComplexMatrices
  from geomstats.geometry.complex_riemannian_metric import ComplexRiemannianMetric
  from geomstats.geometry.hermitian_matrices import expmh, powermh
  from geomstats.geometry.matrices import Matrices
label_desc: Use image node_id 6 for calling the SiegelMetric obj's underlying member method code with example usage: obj.log_at_zero(point) and returns: unknown