import numpy as npimport matplotlib.pyplot as pltnp.random.seed(0)data = np.random.randint(0, 3, size=(100,100))colors = dict((                (0, (0, 255, 0, 255)), # 前三位RGB，255代表256色                (1, (0, 0, 255, 255)),                  (2, (255, 255, 0, 255)),               ))# 转换为0-1for k in colors:    v = colors[k]    _v = [_v / 255.0 for _v in v]    colors[k] = _v    index_colors = [colors[key] if key in colors else                (255, 255, 255, 0) for key in range(0, len(colors))]cmap = plt.matplotlib.colors.ListedColormap(index_colors, 'Classification', len(index_colors)) # n等于颜色表长度，否则被截断或被重复# cmap = plt.matplotlib.colors.ListedColormap(['gray', 'orange', 'k'], 'Classification')plt.rcParams['font.family'] = 'Arial'plt.rcParams['font.size'] = 10plt.rcParams['font.weight'] = 'bold'fig, ax = plt.subplots(figsize=(4,3.5), dpi=300)ax.imshow(data, cmap=cmap, interpolation='none')# 绘制矩形的补丁, 用来生成图例，fig.add_artist()才会在图中显示出来 import matplotlib.patches as mpatches rectangles = [mpatches.Rectangle((0, 0,), 1, 1, facecolor=index_colors[i])               for i in range(len(index_colors))]labels = ['forest',          'water',          'urban']ax.legend(rectangles, labels,          bbox_to_anchor=(1.4, 0.25), fancybox=True, frameon=False,)# 取消刻度和标签显示ax.tick_params(which='major', bottom=0, left=0)ax.set_xticklabels('')ax.set_yticklabels('')