code: def set_fraction(self, value):
          
          if value < 0:
              value *= -1
          value = min(value, 1)
          if self.horizontal:
              width = int(self.width * value)
              height = self.height
          else:
              width = self.width
              height = int(self.height * value)
          self.canvas.coords(self.meter, self.xpos, self.ypos,
                             self.xpos + width, self.ypos + height)
docs: Set the meter indicator. Value should be between 0 and 1.