code: def grad_Matern32(ls, x1, x2=None):
      r = np.sqrt(dist2(ls, x1, x2))
      grad_r2 = -1.5 * np.exp(-SQRT_3 * r)
      return grad_r2[:, :, np.newaxis] * grad_dist2(ls, x1, x2)
  
file_path: auptimizer/src/aup/Proposer/spearmint/gp.py
imports: import numpy
  import scipy.linalg
  import scipy.optimize
  import scipy.io
label_desc: Use image node_id 7 for calling a global function with example usage: grad_Matern32(ls, x1, x2) and returns: unknown