code: def analytic_grad(L11=1.0, L22=1.0, L21=1.0, omega1=1.0, omega2=1.0):
      dp = L11 * omega1 + L21 * omega2
      fact_1 = -omega2 * dp
      fact_2 = np.exp(-0.5 * (L22 * omega2) ** 2)
      fact_3 = np.exp(-0.5 * dp**2)
      return fact_1 * fact_2 * fact_3
  
file_path: pyro/tests/distributions/test_omt_mvn.py
imports: import numpy
  import pytest
  import torch
  from pyro.distributions import AVFMultivariateNormal, MultivariateNormal, OMTMultivariateNormal
  from tests.common import assert_equal
label_desc: Use image node_id 1 for calling a global function with example usage: analytic_grad(L11, L22, L21, omega1, omega2) and returns: unknown