code: def rad_fn(x, pos=None):
      """Radian function formatter."""
      n = int((x / np.pi) * 2.0 + 0.25)
      if n == 0:
          return str(x)
      elif n == 1:
          return r"$\pi/2$"
      elif n == 2:
          return r"$\pi$"
      elif n % 2 == 0:
          return r"$%s\pi$" % (n / 2,)
      else:
          return r"$%s\pi/2$" % (n,)
  
file_path: catboost/contrib/python/matplotlib/py2/matplotlib/testing/jpl_units/UnitDblConverter.py
imports: from __future__ import absolute_import, division, print_function, unicode_literals
  import six
  import numpy
  import matplotlib.units
  import matplotlib.projections.polar
  from matplotlib.cbook import iterable
label_desc: Use image node_id 1 for calling a global function with example usage: rad_fn(x, pos) and returns: str, str, str, unknown, unknown