code: def parallel_check(vec1, vec2):
      
  
      # Imports
      from ..const import PRM
      import numpy as np
  
      # Initialize False
      par = False
  
      # Shape check
      for n,v in enumerate([vec1, vec2]):
          if not len(v.shape) == 1:
              raise ValueError("Bad shape for vector #{0}".format(n))
          ## end if
      ## next v,n
      if not vec1.shape[0] == vec2.shape[0]:
          raise ValueError("Vector length mismatch")
      ## end if
  
      # Check for (anti-)parallel character and return
      angle = vec_angle(vec1, vec2)
      if min([abs(angle), abs(angle - 180.)]) < PRM.NON_PARALLEL_TOL:
          par = True
      ## end if
  
      return par
docs: Checks whether two vectors are parallel OR anti-parallel.
  
      Vectors must be of the same dimension.
  
      Parameters
      ----------
      vec1
          length-R |npfloat_| --
          First vector to compare
  
      vec2
          length-R |npfloat_| --
          Second vector to compare
  
      Returns
      -------
      par
          |bool| --
          |True| if (anti-)parallel to within
          :data:`opan.const.PRM.NON_PARALLEL_TOL` degrees.  |False| otherwise.