text: import math
  
  import matplotlib.pyplot as plt
  from matplotlib import rc
  import numpy as np
  
  if __name__ == '__main__':
      # init config
      x_limit = math.pi * 2
      c = 2
  
      # rc('font', **{'family': 'sans-serif', 'sans-serif': ['Helvetica']})
      # for 'Palatino' and other serif fonts use:
      # rc('font',**{'family':'serif','serif':['Palatino']})
      # rc('text', usetex=True)
  
      # domain and co-domain settings
      x = np.linspace(-x_limit, x_limit, 100)
      f_x = np.sin(x)
  
      # upper function
      g_x = f_x + c
  
      # lower function
      h_x = f_x - c
  
      plt.figure(1)
  
      plt.plot(x, g_x, 'g--')
      plt.plot(x, f_x)
      plt.plot(x, h_x, 'y--')
  
      # get/set the x limits of the current axes
      plt.xlim(-math.pi, math.pi)
  
      # get/set the y limits of the current axes
      plt.ylim(-math.pi, math.pi)
  
      # add a horizontal line across the axis
      plt.axhline(y=0, color='k')
  
      # add a vertical line across the axes
      plt.axvline(x=0, color='k')
  
      # *math_fontfamily* can be used in most places where there is text,
      # like in the title:
      # plt.title(r"$f(x)\pm c$", size=14)  # , **code_font
  
      # save plot to file
      # after plt.show() is called, a new blank figure is created.
      # to avoid paving black images, just save the image before showing it
      plt.savefig('y_translation.svg')
  
      # display all open figures
      plt.show()
  
      # print(matplotlib.font_manager.fontManager.ttflist)
  
  # https://stackoverflow.com/questions/21321670/how-to-change-fonts-in-matplotlib-python#21323217
  # https://matplotlib.org/stable/api/_as_gen/matplotlib.pyplot.plot.html
  # https://python.astrotech.io/matplotlib/multiple-figures.html#multiple-plots-on-one-figure
  