Python - 2 / 3D散点图,其中包含来自该数据的表面图

时间:2018-01-01 20:23:26

标签: python numpy matplotlib plot

使用:[python] [numpy] [matplotlib] 所以我有一个3D数组来创建一个散点图,形成一个n * n * n立方体。这些点具有由颜色表示的不同潜在值。 You can see the results here.

size = 11
z = y = x = size
potential = np.zeros((z, y, x))                                                
Positive = 10
Negative = -10

""" ------- Positive Polo --------- """                                        
polox = poloy = poloz = [1,2]
polos=[polox,poloy,poloz]
polop = [list(x) for x in np.stack(np.meshgrid(*polos)).T.reshape(-1,len(polos))] # Positive polos list

for coord in polop:
    potential[coord] = Positive

""" ------- Negative Polo --------- """                                        
polo2x = polo2y = polo2z = [size-3,size-2]
polos2=[polo2x,polo2y,polo2z]
polon = [list(x) for x in np.stack(np.meshgrid(*polos2)).T.reshape(-1,len(polos2))] # Negative polos list

for coord in polon:
    potential[coord] = Negative

我在开始时有2个值为-10和10的polos,其余的点数计算如下:(周围点的平均值,没有对角线):

for z in range(1,size):
    for y in range(1,size):
        for x in range(1,size):
            if [z,y,x] in polop:
                potential[z,y,x] = Positive                                # If positive polo, keeps potential
            elif [z,y,x] in polon:
                potential[z,y,x] = Negative                                # If negative polo, keeps potential
            elif z!=size-1 and y!=size-1 and x!=size-1:                    # Sets the potential to the mean potential of neighbors
                potential[z][y][x] = (potential[z][y][x+1] + potential[z][y][x-1] + potential[z][y+1][x] + potential[z][y-1][x] + potential[z+1][y][x] + potential[z-1][y][x]) / 6

对于外部细胞:

for z in range(0,size):
        for y in range(0,size):
            for x in range(0,size):
                potential[z,y,0] = potential[z,y,2]
                potential[z,0,x] = potential[z,2,x]
                potential[0,y,x] = potential[2,y,x]
                if z == size-1:
                    potential[size-1,y,x] = potential[size-3,y,x]
                elif y == size-1:
                    potential[z,size-1,x] = potential[z,size-3,x]
                elif x == size-1:
                    potential[z,y,size-1] = potential[z,y,size-3]

我需要的是是显示连接具有相同值间隔的相同颜色的点的表面' (如从0到2.5)。

我知道有很多这样的问题,但我无法适应我的代码,它既不会显示(例如this),也不会显示不是同一个问题,或者它不是python(如this one),这就是我再次提问的原因。 它也可以显示为许多具有曲面的子图。

注意:我的3D数组是这样的,如果我输入print(potential [1,1,1]),它会显示该单元格的值,正如您在下图中看到的那样,它是10.而那个&#39我用什么来显示颜色。

fig = plt.figure()
ax = fig.add_subplot(111, projection='3d')
z,y,x = potential.nonzero()
cube = ax.scatter(x, y, z, zdir='z', c=potential[z,y,x], cmap=plt.cm.rainbow)  # Plot the cube
cbar = fig.colorbar(cube, shrink=0.6, aspect=5)                                # Add a color bar which maps values to colors.

1 个答案:

答案 0 :(得分:0)

创建Minimum, Complete and Verifiable Example以便更轻松地帮助您将非常有用。

我仍然不清楚你的意思是如何计算你的潜力,也不清楚你是如何产生你的表面的,所以我已经包含了琐碎的功能。

下面的代码将生成彩色点的3D散点图和具有平均颜色值的Surface。

from mpl_toolkits.mplot3d import Axes3D
import matplotlib.pyplot as plt
import numpy as np

def fn(x, y):
    """Custom fuction to determine the colour (potential?) of the point"""
    return (x + y) / 2  # use average as a placeholder

fig = plt.figure()
ax = fig.add_subplot(111, projection='3d')

size = 11  # range 0 to 10
# Make the 3D grid
X, Y, Z = np.meshgrid(np.arange(0, size, 1),
                      np.arange(0, size, 1),
                      np.arange(0, size, 1))

# calculate a colour for point(x,y,z)
zs = np.array([fn(x, y) for x, y in zip(np.ravel(X), np.ravel(Y))])
ZZ = zs.reshape(X.shape)  # this is used below

# create the surface
xx, yy = np.meshgrid(np.arange(0, size, 1), np.arange(0, size, 1))
# Calcule the surface Z value, e.g. average of  the colours calculated above
zzs = np.array([np.average(ZZ[x][y]) for x, y in zip(np.ravel(xx), np.ravel(yy))])
zz= zzs.reshape(xx.shape)

cube = ax.scatter(X, Y, Z, zdir='z', c=zs, cmap=plt.cm.rainbow)
surf = ax.plot_surface(xx, yy, zz, cmap=plt.cm.rainbow) 
cbar = fig.colorbar(cube, shrink=0.6, aspect=5) # Add a color bar

plt.show()

生成的图像看起来像这样: 3D Scatter and Surface

编辑:使用您的附加代码,我可以复制您的多维数据集。

然后使用以下代码生成表面:

xx, yy = np.meshgrid(np.arange(0, size, 1), np.arange(0, size, 1))
#define potential range
min_p = 1.0
max_p = 4.0

zz = np.zeros((size, size))
for i in range(size):  # X
    for j in range(size):  # Y
        for k in range(size):  # Z
            p = potential[k,j,i]
            if min_p < p < max_p:
                zz[j][i] = p # stop at the first element to meet the conditions
                break # break to use the first value in range

然后绘制这个表面:

surf = ax.plot_surface(xx, yy, zz, cmap=plt.cm.rainbow) 

注意:包含vmin和vmax关键字args以保持相同的比例,我将它们排除在外以便表面偏差更明显。我还将立方体上的alpha设置为0.2,以便更容易看到表面。

Cube plot with Surface take 2