code: def cplot(
      ctx,
      f,
      re=[-5, 5],
      im=[-5, 5],
      points=2000,
      color=None,
      verbose=False,
      file=None,
      dpi=None,
      axes=None,
  ):
      """
      Plots the given complex-valued function *f* over a rectangular part
      of the complex plane specified by the pairs of intervals *re* and *im*.
      For example::
  
          cplot(lambda z: z, [-2, 2], [-10, 10])
          cplot(exp)
          cplot(zeta, [0, 1], [0, 50])
  
      By default, the complex argument (phase) is shown as color (hue) and
      the magnitude is show as brightness. You can also supply a
      custom color function (*color*). This function should take a
      complex number as input and return an RGB 3-tuple containing
      floats in the range 0.0-1.0.
  
      Alternatively, you can select a builtin color function by passing
      a string as *color*:
  
        * "default" - default color scheme
        * "phase" - a color scheme that only renders the phase of the function,
           with white for positive reals, black for negative reals, gold in the
           upper half plane, and blue in the lower half plane.
  
      To obtain a sharp image, the number of points may need to be
      increased to 100,000 or thereabout. Since evaluating the
      function that many times is likely to be slow, the 'verbose'
      option is useful to display progress.
  
      .. note :: This function requires matplotlib (pylab).
      """
      if color is None or color == "default":
          color = ctx.default_color_function
      if color == "phase":
          color = ctx.phase_color_function
      import pylab
  
      if file:
          axes = None
      fig = None
      if not axes:
          fig = pylab.figure()
          axes = fig.add_subplot(111)
      rea, reb = re
      ima, imb = im
      dre = reb - rea
      dim = imb - ima
      M = int(ctx.sqrt(points * dre / dim) + 1)
      N = int(ctx.sqrt(points * dim / dre) + 1)
      x = pylab.linspace(rea, reb, M)
      y = pylab.linspace(ima, imb, N)
      # Note: we have to be careful to get the right rotation.
      # Test with these plots:
      #   cplot(lambda z: z if z.real < 0 else 0)
      #   cplot(lambda z: z if z.imag < 0 else 0)
      w = pylab.zeros((N, M, 3))
      for n in xrange(N):
          for m in xrange(M):
              z = ctx.mpc(x[m], y[n])
              try:
                  v = color(f(z))
              except ctx.plot_ignore:
                  v = (0.5, 0.5, 0.5)
              w[n, m] = v
          if verbose:
              print(str(n) + " of " + str(N))
      rea, reb, ima, imb = [float(_) for _ in [rea, reb, ima, imb]]
      axes.imshow(w, extent=(rea, reb, ima, imb), origin="lower")
      axes.set_xlabel("Re(z)")
      axes.set_ylabel("Im(z)")
      if fig:
          if file:
              pylab.savefig(file, dpi=dpi)
          else:
              pylab.show()
  
file_path: catboost/contrib/python/mpmath/py3/mpmath/visualization.py
imports: from colorsys import hsv_to_rgb, hls_to_rgb
  from .libmp import NoConvergence
  from .libmp.backend import xrange
label_desc: Use image node_id 4 for calling a global function with example usage: cplot(ctx, f, re, im, points, color, verbose, file, dpi, axes) without return types