class_docstr: Class for the Fisher information metric on Poisson distributions.
  
  References
  ----------
  .. [AM1981] Atkinson, C., & Mitchell, A. F. (1981). Rao's distance measure.
      Sankhyā: The Indian Journal of Statistics, Series A, 345-365.
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docstr: Solve geodesic initial value problem.
  
  Compute the parameterized function for the geodesic starting at
  initial_point with initial velocity given by initial_tangent_vec.
  
  Parameters
  ----------
  initial_point : array-like, shape=[..., 1]
      Initial point.
  
  initial_tangent_vec : array-like, shape=[..., 1]
      Tangent vector at initial point.
  
  Returns
  -------
  path : function
      Parameterized function for the geodesic curve starting at
      initial_point with velocity initial_tangent_vec.
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code: def _geodesic_ivp(self, initial_point, initial_tangent_vec):
      """Solve geodesic initial value problem.
  
      Compute the parameterized function for the geodesic starting at
      initial_point with initial velocity given by initial_tangent_vec.
  
      Parameters
      ----------
      initial_point : array-like, shape=[..., 1]
          Initial point.
  
      initial_tangent_vec : array-like, shape=[..., 1]
          Tangent vector at initial point.
  
      Returns
      -------
      path : function
          Parameterized function for the geodesic curve starting at
          initial_point with velocity initial_tangent_vec.
      """
      constant_a = initial_tangent_vec / (2 * gs.sqrt(initial_point))
      constant_b = gs.sqrt(initial_point)
      return lambda t: self._geodesic_path(t, constant_a, constant_b)
  
imports: from scipy.special import factorial
  from scipy.stats import poisson
  import geomstats.backend
  from geomstats.geometry.base import VectorSpaceOpenSet
  from geomstats.geometry.euclidean import Euclidean
  from geomstats.geometry.riemannian_metric import RiemannianMetric
  from geomstats.information_geometry.base import InformationManifoldMixin, ScipyUnivariateRandomVariable
label_desc: Use image node_id 4 for calling the PoissonMetric obj's underlying member method code with example usage: obj._geodesic_ivp(initial_point, initial_tangent_vec) and returns: function