class_docstr: Refer to FigureFactory.create_streamline() for docstring
code: def __init__(self, x, y, u, v, density, angle, arrow_scale, **kwargs):
      self.x = np.array(x)
      self.y = np.array(y)
      self.u = np.array(u)
      self.v = np.array(v)
      self.angle = angle
      self.arrow_scale = arrow_scale
      self.density = int(
          30 * density
      )  # Scale similarly to other functions
      self.delta_x = self.x[1] - self.x[0]
      self.delta_y = self.y[1] - self.y[0]
      self.val_x = self.x
      self.val_y = self.y
  
      # Set up spacing
      self.blank = np.zeros((self.density, self.density))
      self.spacing_x = len(self.x) / float(self.density - 1)
      self.spacing_y = len(self.y) / float(self.density - 1)
      self.trajectories = []
  
      # Rescale speed onto axes-coordinates
      self.u = self.u / (self.x[-1] - self.x[0])
      self.v = self.v / (self.y[-1] - self.y[0])
      self.speed = np.sqrt(self.u**2 + self.v**2)
  
      # Rescale u and v for integrations.
      self.u *= len(self.x)
      self.v *= len(self.y)
      self.st_x = []
      self.st_y = []
      self.get_streamlines()
      streamline_x, streamline_y = self.sum_streamlines()
      arrows_x, arrows_y = self.get_streamline_arrows()
  
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 1 to create a new _Streamline object from inherited base classes: object with example: obj = _Streamline(x, y, u, v, density, angle, arrow_scale)