Python 之 matplotlib (八)Bar__Python

代碼：

import matplotlib.pyplot as pltimport numpy as npn = 12X = np.arange(n)Y1 = (1 - X / float(n)) * np.random.uniform(0.5, 1.0, n)Y2 = (1 - X / float(n)) * np.random.uniform(0.5, 1.0, n)plt.bar(X, +Y1, facecolor='#9999ff', edgecolor='white')plt.bar(X, -Y2, facecolor='#ff9999', edgecolor='white')# 加上數值for x, y in zip(X, Y1):    # ha:horizontal alignment    plt.text(x, y + 0.05, '%.2f' % y, ha='center', va='bottom')for x, y in zip(X, Y2):    # ha:horizontal alignment    plt.text(x, -y - 0.05, '-%.2f' % y, ha='center', va='top')plt.xlim(-.5, n)plt.xticks(())plt.ylim(-1.25, 1.25)plt.yticks(())plt.show()

運行結果：