code: def vector_cos(self, vec):
      assert len(vec) == 2
      return vec[0] / (norm(vec) + self.eps)
  
imports: import cv2
  import numpy
  from ppocr.utils.utility import check_install
  from numpy.linalg import norm
label_desc: Use image node_id 5 for calling the DRRGTargets obj's underlying member method code with example usage: obj.vector_cos(vec) and returns: unknown