如何將標籤註釋到3D matplotlib散點圖？

Question

我對3個主要組件（PC1，PC2，PC3）的數據進行了sklearn - 主成分分析。數據看起來是這樣的（這是一個熊貓數據幀）：

這裏是繪製原理組件的代碼：

from mpl_toolkits.mplot3d import axes3d 
import matplotlib.pyplot as plt 
%matplotlib 
fig = plt.figure() 
ax = fig.gca(projection='3d') 
ax.set_title('3D Scatter Plot') 
ax.set_xlabel('PC1') 
ax.set_ylabel('PC2') 
ax.set_zlabel('PC3') 

ax.view_init(elev=12, azim=40)    # elevation and angle 
ax.dist=10         # distance 
ax.scatter(
     data_df_3dx['PC1'], data_df_3dx['PC2'], data_df_3dx['PC3'], # data 
     #color='purple',       # marker colour 
     #marker='o',        # marker shape 
     s=60          # marker size 
     ) 

plt.show() 

我的問題，我怎麼添加標籤（如「GER，中」 ）的要點？希望有人可以幫助我:)

Answer 1

一種方法是將每個點分別繪製在for循環中，這樣您就知道每個點的座標並可以向其中添加文本。

for i in range(len(data_df_3dx)): 
    x, y, z = data_df_3dx.iloc[i]['PC1'], data_df_3dx.iloc[i]['PC2'], data_df_3dx.iloc[i]['PC3'] 
    ax.scatter(x, y, z) 
    #now that you have the coordinates you can apply whatever text you need. I'm 
    #assuming you want the index, but you could also pass a column name if needed 
    ax.text(x, y, z, '{0}'.format(data_df_3dx.index[i]), size=5) 

Answer 2

在下面的帖子[1]，[2] 3D箭頭在matplotlib繪製了討論。 （從註釋繼承）

同樣Annotation3D類可以被創建：

from mpl_toolkits.mplot3d.proj3d import proj_transform 
from matplotlib.text import Annotation 

class Annotation3D(Annotation): 
    '''Annotate the point xyz with text s''' 

    def __init__(self, s, xyz, *args, **kwargs): 
     Annotation.__init__(self,s, xy=(0,0), *args, **kwargs) 
     self._verts3d = xyz   

    def draw(self, renderer): 
     xs3d, ys3d, zs3d = self._verts3d 
     xs, ys, zs = proj_transform(xs3d, ys3d, zs3d, renderer.M) 
     self.xy=(xs,ys) 
     Annotation.draw(self, renderer) 

此外，我們可以定義annotate3D（）函數：

def annotate3D(ax, s, *args, **kwargs): 
    '''add anotation text s to to Axes3d ax''' 

    tag = Annotation3D(s, *args, **kwargs) 
    ax.add_artist(tag) 

使用此功能註釋標籤可以被添加到Axes3d如下例所示：

import matplotlib.pyplot as plt  
from mpl_toolkits.mplot3d import axes3d 
from mpl_toolkits.mplot3d.art3d import Line3DCollection 

# data: coordinates of nodes and links 
xn = [1.1, 1.9, 0.1, 0.3, 1.6, 0.8, 2.3, 1.2, 1.7, 1.0, -0.7, 0.1, 0.1, -0.9, 0.1, -0.1, 2.1, 2.7, 2.6, 2.0] 
yn = [-1.2, -2.0, -1.2, -0.7, -0.4, -2.2, -1.0, -1.3, -1.5, -2.1, -0.7, -0.3, 0.7, -0.0, -0.3, 0.7, 0.7, 0.3, 0.8, 1.2] 
zn = [-1.6, -1.5, -1.3, -2.0, -2.4, -2.1, -1.8, -2.8, -0.5, -0.8, -0.4, -1.1, -1.8, -1.5, 0.1, -0.6, 0.2, -0.1, -0.8, -0.4] 
group = [1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 3, 2, 2, 2, 3, 3, 3, 3] 
edges = [(1, 0), (2, 0), (3, 0), (3, 2), (4, 0), (5, 0), (6, 0), (7, 0), (8, 0), (9, 0), (11, 10), (11, 3), (11, 2), (11, 0), (12, 11), (13, 11), (14, 11), (15, 11), (17, 16), (18, 16), (18, 17), (19, 16), (19, 17), (19, 18)] 
xyzn = zip(xn, yn, zn) 
segments = [(xyzn[s], xyzn[t]) for s, t in edges]     

# create figure   
fig = plt.figure(dpi=60) 
ax = fig.gca(projection='3d') 
ax.set_axis_off() 

# plot vertices 
ax.scatter(xn,yn,zn, marker='o', c = group, s = 64)  
# plot edges 
edge_col = Line3DCollection(segments, lw=0.2) 
ax.add_collection3d(edge_col) 
# add vertices annotation. 
for j, xyz_ in enumerate(xyzn): 
    annotate3D(ax, s=str(j), xyz=xyz_, fontsize=10, xytext=(-3,3), 
       textcoords='offset points', ha='right',va='bottom')  
plt.show()