code: def forward_cpu(self, x):
      global _lgamma_cpu
      if _lgamma_cpu is None:
          try:
              from scipy import special
  
              _lgamma_cpu = special.gammaln
          except ImportError:
              raise ImportError(
                  "SciPy is not available. Forward computation"
                  " of lgamma can not be done."
              )
      self.retain_inputs((0,))
      return (utils.force_array(_lgamma_cpu(x[0]), dtype=x[0].dtype),)
  
file_path: chainer/chainer/functions/math/lgamma.py
imports: import chainer
  from chainer.backends import cuda
  from chainer import function_node
  from chainer import utils
  from chainer.utils import type_check
label_desc: Use image node_id 3 for calling the LGamma obj's underlying member method code with example usage: obj.forward_cpu(x) and returns: utils