code: def ramp_response_plot(
      system,
      slope=1,
      color="b",
      prec=8,
      lower_limit=0,
      upper_limit=10,
      show_axes=False,
      grid=True,
      show=True,
      **kwargs,
  ):
      r"""
      Returns the ramp response of a continuous-time system.
  
      Ramp function is defined as the straight line
      passing through origin ($f(x) = mx$). The slope of
      the ramp function can be varied by the user and
      the default value is 1.
  
      Parameters
      ==========
  
      system : SISOLinearTimeInvariant type
          The LTI SISO system for which the Ramp Response is to be computed.
      slope : Number, optional
          The slope of the input ramp function. Defaults to 1.
      color : str, tuple, optional
          The color of the line. Default is Blue.
      show : boolean, optional
          If ``True``, the plot will be displayed otherwise
          the equivalent matplotlib ``plot`` object will be returned.
          Defaults to True.
      lower_limit : Number, optional
          The lower limit of the plot range. Defaults to 0.
      upper_limit : Number, optional
          The upper limit of the plot range. Defaults to 10.
      prec : int, optional
          The decimal point precision for the point coordinate values.
          Defaults to 8.
      show_axes : boolean, optional
          If ``True``, the coordinate axes will be shown. Defaults to False.
      grid : boolean, optional
          If ``True``, the plot will have a grid. Defaults to True.
  
      Examples
      ========
  
      .. plot::
          :context: close-figs
          :format: doctest
          :include-source: True
  
          >>> from sympy.abc import s
          >>> from sympy.physics.control.lti import TransferFunction
          >>> from sympy.physics.control.control_plots import ramp_response_plot
          >>> tf1 = TransferFunction(s, (s+4)*(s+8), s)
          >>> ramp_response_plot(tf1, upper_limit=2)   # doctest: +SKIP
  
      See Also
      ========
  
      step_response_plot, impulse_response_plot
  
      References
      ==========
  
      .. [1] https://en.wikipedia.org/wiki/Ramp_function
  
      """
      x, y = ramp_response_numerical_data(
          system,
          slope=slope,
          prec=prec,
          lower_limit=lower_limit,
          upper_limit=upper_limit,
          **kwargs,
      )
      plt.plot(x, y, color=color)
      plt.xlabel("Time (s)")
      plt.ylabel("Amplitude")
      plt.title(
          f"Ramp Response of ${latex(system)}$ [Slope = {slope}]",
          pad=20,
      )
  
      if grid:
          plt.grid()
      if show_axes:
          plt.axhline(0, color="black")
          plt.axvline(0, color="black")
      if show:
          plt.show()
          return
  
      return plt
  
imports: from sympy.core.numbers import I, pi
  from sympy.functions.elementary.exponential import exp, log
  from sympy.polys.partfrac import apart
  from sympy.core.symbol import Dummy
  from sympy.external import import_module
  from sympy.functions import arg, Abs
  from sympy.integrals.laplace import _fast_inverse_laplace
  from sympy.physics.control.lti import SISOLinearTimeInvariant
  from sympy.plotting.series import LineOver1DRangeSeries
  from sympy.polys.polytools import Poly
  from sympy.printing.latex import latex
label_desc: Use image node_id 9 for calling a global function with example usage: ramp_response_plot(system, slope, color, prec, lower_limit, upper_limit, show_axes, grid, show) and returns: plt