matplotlib預設的座標原點在左下角；有時候你想將它變換到左上角。程式碼如下：

Code Example :

from matplotlib.lines import Line2D
import matplotlib.pyplot as plt

figure, ax = plt.subplots()

# 設定x，y值域
ax.set_xlim(left=0, right=20)
ax.set_ylim(bottom=10, top=0)  # 此處將原點設定為左上角
ax.xaxis.tick_top()  # 將x座標標記移到上方
# 兩條line的資料
line1 = [(1, 1), (5
 
, 5)]
line2 = [(11, 9), (8, 8)]
(line1_xs, line1_ys) = zip(*line1)
(line2_xs, line2_ys) = zip(*line2)
# 建立兩條線，並新增
ax.add_line(Line2D(line1_xs, line1_ys, linewidth=1, color='blue'))
ax.add_line(Line2D(line2_xs, line2_ys, linewidth=1, color='red'))
# 展示
plt.plot()
plt.show()

Output :

Ref: