可不可以解释一下以下的代码from matplotlib import cbook from matplotlib import cm from matplotlib.colors import LightSource import matplotlib.pyplot as plt import numpy as np dem = cbook.get_sample_data('jacksboro_fault_dem.npz', np_load=True) z = dem['elevation'] nrows, ncols = z.shape x = np.linspace(dem['xmin'], dem['xmax'], ncols) y = np.linspace(dem['ymin'], dem['ymax'], nrows) x, y = np.meshgrid(x, y) region = np.s_[5:50, 5:50] x, y, z = x[region], y[region], z[region] fig, ax = plt.subplots(subplot_kw=dict(projection='3d')) ls = LightSource(270, 45) rgb = ls.shade(z, cmap=cm.gist_earth, vert_exag=0.1, blend_mode='soft') surf = ax.plot_surface(x, y, z, rstride=1, cstride=1, facecolors=rgb, linewidth=0, antialiased=False, shade=False) plt.show()

这段代码是用来创建一个三维曲面图的，它从文件中获取数据，然后使用LightSource函数创建RGB（红色、绿色和蓝色）颜色，使用plot_surface函数绘制曲面，最后通过plt.show（）函数显示绘制的曲面图。