matplotlib实现三维柱状图
matplotlib实现三维柱状图
1 import cv2 2 3 img = cv2.imread("1.png", 0) 4 5 #特征点在图片中的坐标位置 6 m = 448 7 n = 392 8 9 import numpy as np 10 import matplotlib.pyplot as plt 11 12 # This import registers the 3D projection, but is otherwise unused. 13 from mpl_toolkits.mplot3d import Axes3D # noqa: F401 unused import 14 15 # setup the figure and axes 16 fig = plt.figure(figsize=(10, 5)) # 画布宽长比例 17 ax1 = fig.add_subplot(121, projection='3d') 18 ax2 = fig.add_subplot(122, projection='3d') 19 ax1.set_title('Shaded') 20 ax2.set_title("colored") 21 22 # fake data 23 _x = np.arange(444, 453) 24 _y = np.arange(388, 397) 25 _xx, _yy = np.meshgrid(_x, _y) 26 x, y = _xx.ravel(), _yy.ravel()#ravel扁平化 27 # 函数 28 top = [] 29 for i in range(-4, 5): 30 for j in range(-4, 5): 31 top.append(img[i+n][j+m]) 32 33 bottom = np.zeros_like(top)#每个柱的起始位置 34 width = depth = 1#x,y方向的宽厚 35 36 ax1.bar3d(x, y, bottom, width, depth, top, shade=True) #x，y为数组 37 38 ax1.set_xlabel('X') 39 ax1.set_ylabel('Y') 40 ax1.set_zlabel('pixel value') 41 42 for i in range(-4, 5): 43 for j in range(-4, 5): 44 z = img[i+n][j+m] #该柱的高 45 color = np.array([255, 255, z])/255.0#颜色 其中每个元素在0~1之间 46 ax2.bar3d(j+m, i+n, 0, width, depth, z, color=color) #每次画一个柱 47 48 ax2.set_xlabel('X') 49 ax2.set_ylabel('Y') 50 ax2.set_zlabel('pixel value') 51 plt.show()
以上程序将特征点周围四个像素的像素点三维化，ax1用数组的方式画柱状图，同时绘制多个柱。ax2用数值的方式画柱状图，每次画一个柱。
结果：
