Plotly + Python：如何在3D中繪製箭頭？

Question

我正在使用Plotly + Python。如何以3D形式繪製單個矢量，如箭頭所示？

註解（這本來就是一個怪異的解決方法）是2D的，而顫抖圖也是2D的。

Answer 1

正如邁克·懷斯所說，這是不可能做到這一點筆直向前，不過，你可以計算出您的載體，然後通過畫線到原點繪製它：

例如： 情節在一些點3D和繪製對應於這些點的質心向量

import plotly.graph_objs as go 
from plotly.offline import plot 

#prepare plotting points 
#points are: (0,5,5),(5,0,0),(5,10,5),(10,5,5) 
points = go.Scatter3d(x = [0,5,5,10], 
         y = [5,0,10,5], 
         z = [5,0,5,0], 
         mode = 'markers', 
         marker = dict(size = 2, 
             color = "rgb(227,26,28)") 
        ) 
#Compute centroid of all 3 points by taking the mean of each of 
#its coordinates (not sure this is the right definition of centroid) 
centerX = (0+5+5+10)/float(4) 
centerY = (5+0+10+5)/float(4) 
centerZ = (5+0+5+0)/float(4) 

#Prepare centroid vector 
vector = go.Scatter3d(x = [0,centerX], 
         y = [0,centerY], 
         z = [0,centerZ], 
         marker = dict(size = 1, 
             color = "rgb(84,48,5)"), 
         line = dict(color = "rgb(84,48,5)", 
            width = 6) 
        ) 
data = [points,vector] 
layout = go.Layout(margin = dict(l = 0, 
            r = 0, 
            b = 0, 
            t = 0) 
       ) 
fig = go.Figure(data=data,layout=layout) 
plot(fig,filename="vector.html",auto_open=False,image='png',image_height=800,image_width=1500) 

這將產生：

如果您打開交互式html文件將會好得多