code: def _calc_projection(x, mean, eps, groups):
      xs = numpy.split(x, groups, axis=1)
      assert mean.shape[0] == groups
      projections = [
          _calc_projection_1group(xi, m, eps)
          for (xi, m) in zip(xs, mean)
      ]
      return numpy.concatenate([p[None] for p in projections])
  
imports: import contextlib
  import os
  import tempfile
  import unittest
  import numpy
  import chainer
  from chainer import links
  from chainer import testing
label_desc: Use image node_id 3 for calling a global function with example usage: _calc_projection(x, mean, eps, groups) and returns: numpy