class_docstr: Refer to FigureFactory.create_streamline() for docstring
docstr: Integrate trajectories
  
  :param (int) xb: results of passing xi through self.blank_pos
  :param (int) xy: results of passing yi through self.blank_pos
  
  Calculate each trajectory based on rk4 integrate method.
docstr_tok: ["Integrate","trajectories",":","param","(","int",")","xb",":","results","of","passing","xi","through","self.blank_pos",":","param","(","int",")","xy",":","results","of","passing","yi","through","self.blank_pos","Calculate","each","trajectory","based","on","rk4","integrate","method","."]
code: def traj(self, xb, yb):
      """
      Integrate trajectories
  
      :param (int) xb: results of passing xi through self.blank_pos
      :param (int) xy: results of passing yi through self.blank_pos
  
      Calculate each trajectory based on rk4 integrate method.
      """
  
      if xb < 0 or xb >= self.density or yb < 0 or yb >= self.density:
          return
      if self.blank[yb, xb] == 0:
          t = self.rk4_integrate(
              xb * self.spacing_x, yb * self.spacing_y
          )
          if t is not None:
              self.trajectories.append(t)
  
file_path: plotly.py/packages/python/plotly/plotly/figure_factory/_streamline.py
imports: import math
  from plotly import exceptions, optional_imports
  from plotly.figure_factory import utils
  from plotly.graph_objs import graph_objs
label_desc: Use image node_id 5 for calling the _Streamline obj's underlying member method code with example usage: obj.traj(xb, yb) without return types