docstr: Kernel for a single layer
docstr_tok: ["Kernel","for","a","single","layer"]
code: def _single_layer_K(
      self, x1norm, x2norm, x1sum, x2sum, cos_theta, x2_none=False
  ):
      """
      Kernel for a single layer
      """
      theta = np.arccos(cos_theta)
  
      return (
          x1norm
          * x2norm
          * (
              np.square(1 - self.a)
              / (2 * np.pi)
              * (np.sin(theta) + (np.pi - theta) * np.cos(theta))
              + self.a * np.cos(theta)
          )
      )
  
file_path: elu-gelu-kernels/code/kernels/nn_kernel_lrelu.py
imports: import numpy
  from scipy.stats import multivariate_normal
  from scipy.stats import norm
  from scipy.special import erf
  import GPy
  import abc
  from .nn_kernel import NNKernel
  from .nn_kernel_linear import NNKernelLinear
  from .nn_kernel_abs import NNKernelAbs
label_desc: Use image node_id 2 for calling the NNKernelLRelu obj's underlying member method code with example usage: obj._single_layer_K(x1norm, x2norm, x1sum, x2sum, cos_theta, x2_none) and returns: unknown