code: def _unsafe_standard_stable(alpha, beta, V, W, coords):
      # Implements a noisily reparametrized version of the sampler
      # Chambers-Mallows-Stuck method as corrected by Weron [1,3] and simplified
      # by Nolan [4]. This will fail if alpha is close to 1.
  
      # Differentiably transform noise via parameters.
      assert V.shape == W.shape
      inv_alpha = alpha.reciprocal()
      half_pi = math.pi / 2
      eps = torch.finfo(V.dtype).eps
      # make V belong to the open interval (-pi/2, pi/2)
      V = V.clamp(min=2 * eps - half_pi, max=half_pi - 2 * eps)
      ha = half_pi * alpha
      b = beta * ha.tan()
      # +/- `ha` term to keep the precision of alpha * (V + half_pi) when V ~ -half_pi
      v = b.atan() - ha + alpha * (V + half_pi)
      Z = (
          v.sin()
          / ((1 + b * b).rsqrt() * V.cos()).pow(inv_alpha)
          * ((v - V).cos().clamp(min=eps) / W).pow(inv_alpha - 1)
      )
      Z.data[Z.data != Z.data] = 0  # drop occasional NANs
  
      # Optionally convert to Nolan's parametrization S^0 where samples depend
      # continuously on (alpha,beta), allowing interpolation around the hole at
      # alpha=1.
      if coords == "S0":
          return Z - b
      elif coords == "S":
          return Z
      else:
          raise ValueError("Unknown coords: {}".format(coords))
  
file_path: pyro/pyro/distributions/stable.py
imports: import math
  import torch
  from torch.distributions import constraints
  from torch.distributions.utils import broadcast_all
  from pyro.distributions.torch_distribution import TorchDistribution
label_desc: Use image node_id 1 for calling a global function with example usage: _unsafe_standard_stable(alpha, beta, V, W, coords) and returns: unknown, Z