class_docstr: Extension of QVector3D which adds a few helpful methods.
docstr: Returns the angle in degrees between this vector and the vector a.
code: def angle(self, a):
      """Returns the angle in degrees between this vector and the vector a."""
      n1 = self.length()
      n2 = a.length()
      if n1 == 0.0 or n2 == 0.0:
          return None
      ## Probably this should be done with arctan2 instead..
      rads = acos(
          fn.clip_scalar(
              QtGui.QVector3D.dotProduct(self, a) / (n1 * n2), -1.0, 1.0
          )
      )  ### in radians
      #        c = self.crossProduct(a)
      #        if c > 0:
      #            ang *= -1.
      return degrees(rads)
  
file_path: pyqtgraph/pyqtgraph/Vector.py
imports: from math import acos, degrees
  from .None import functions
  from .Qt import QT_LIB, QtCore, QtGui
label_desc: Use image node_id 6 for calling the Vector obj's underlying member method code with example usage: obj.angle(a) and returns: degrees, None