code: def translate_y(self, d):
          
          mat = numpy.array([
              [1, 0, 0, 0],
              [0, 1, 0, 0],
              [0, 0, 1, 0],
              [0, d, 0, 1]
          ])
          self.vectors = self.vectors.dot(mat)
          return self
docs: Translate mesh for y-direction
  
          :param float d: Amount to translate