docs: def tickmark(self, x, y, size=10, orientation=90):
          """Draw a line of size and orientation at x,y"""
  
          (x1, y1) = self.p2c([x, y])
          x2 = x1 + size * math.cos(math.radians(orientation))
          y2 = y1 - size * math.sin(math.radians(orientation))
          self.create_line(x1, y1, x2, y2)