## LEDBarGraph > 左上角的條狀圖就是這個類要實現的效果了，就是有若干個指示燈，用亮度來表示不同的范圍。微軟為microbit寫的圖形化編輯器makecode中也有類似的積木塊：  利用`LEDBarGraph`類，我們可以把若干個LED燈的集合看做是一個條形圖。 ~~~ from gpiozero import LEDBarGraph from time import sleep from __future__ import division # required for python 2 graph = LEDBarGraph(5, 6, 13, 19, 26, 20) graph.value = 1 # (1, 1, 1, 1, 1, 1) sleep(1) graph.value = 1/2 # (1, 1, 1, 0, 0, 0) sleep(1) graph.value = -1/2 # (0, 0, 0, 1, 1, 1) sleep(1) graph.value = 1/4 # (1, 0, 0, 0, 0, 0) sleep(1) graph.value = -1 # (1, 1, 1, 1, 1, 1) sleep(1) ~~~ 雖然本質上當`pwm=False`（默認）的時候，LED只有開和關兩種狀態。 但是在使用`LEDBarGraph`的時候，如果我們把pwm設置為真`pwm=True`，那么利用LED亮度來表示條形圖會更加精確。 ~~~ from gpiozero import LEDBarGraph from time import sleep from __future__ import division # required for python 2 graph = LEDBarGraph(5, 6, 13, 19, 26, pwm=True) graph.value = 1/10 # (0.5, 0, 0, 0, 0) sleep(1) graph.value = 3/10 # (1, 0.5, 0, 0, 0) sleep(1) graph.value = -3/10 # (0, 0, 0, 0.5, 1) sleep(1) graph.value = 9/10 # (1, 1, 1, 1, 0.5) sleep(1) graph.value = 95/100 # (1, 1, 1, 1, 0.75) sleep(1) ~~~