我的数据是多维组合数据(所有维度总和为 1 或 100)。我已经学会了如何使用三个变量来创建二维三元图。
我想添加第四个维度,使我的情节看起来像这样。
我愿意使用 python 或 R。我现在正在使用 pyr2
使用 R 在 python 中创建三元图,但这只是因为这是一个简单的解决方案。如果可以将三元数据转换为 3d 坐标,则可以使用简单的线图。
This post 展示了如何将 3d 成分数据转换为 2d 数据,以便可以使用正常的绘图方法。一种解决方案是在 3d 中做同样的事情。
这是一些示例数据:
c1 c2 c3 c4
0 0.082337 0.097583 0.048608 0.771472
1 0.116490 0.065047 0.066202 0.752261
2 0.114884 0.135018 0.073870 0.676229
3 0.071027 0.097207 0.070959 0.760807
4 0.066284 0.079842 0.103915 0.749959
5 0.016074 0.074833 0.044532 0.864561
6 0.066277 0.077837 0.058364 0.797522
7 0.055549 0.057117 0.045633 0.841701
8 0.071129 0.077620 0.049066 0.802185
9 0.089790 0.086967 0.083101 0.740142
10 0.084430 0.094489 0.039989 0.781093
最佳答案
好吧,我自己用 wikipedia article 解决了这个问题, 一个 SO post , 和一些蛮力。对不起,代码墙,但你必须画出所有的情节轮廓和标签等等。
import numpy as np
import matplotlib.pyplot as plt
from mpl_toolkits.mplot3d import axes3d, Axes3D
from itertools import combinations
import pandas as pd
def plot_ax(): #plot tetrahedral outline
verts=[[0,0,0],
[1,0,0],
[0.5,np.sqrt(3)/2,0],
[0.5,0.28867513, 0.81649658]]
lines=combinations(verts,2)
for x in lines:
line=np.transpose(np.array(x))
ax.plot3D(line[0],line[1],line[2],c='0')
def label_points(): #create labels of each vertices of the simplex
a=(np.array([1,0,0,0])) # Barycentric coordinates of vertices (A or c1)
b=(np.array([0,1,0,0])) # Barycentric coordinates of vertices (B or c2)
c=(np.array([0,0,1,0])) # Barycentric coordinates of vertices (C or c3)
d=(np.array([0,0,0,1])) # Barycentric coordinates of vertices (D or c3)
labels=['a','b','c','d']
cartesian_points=get_cartesian_array_from_barycentric([a,b,c,d])
for point,label in zip(cartesian_points,labels):
if 'a' in label:
ax.text(point[0],point[1]-0.075,point[2], label, size=16)
elif 'b' in label:
ax.text(point[0]+0.02,point[1]-0.02,point[2], label, size=16)
else:
ax.text(point[0],point[1],point[2], label, size=16)
def get_cartesian_array_from_barycentric(b): #tranform from "barycentric" composition space to cartesian coordinates
verts=[[0,0,0],
[1,0,0],
[0.5,np.sqrt(3)/2,0],
[0.5,0.28867513, 0.81649658]]
#create transformation array vis https://en.wikipedia.org/wiki/Barycentric_coordinate_system
t = np.transpose(np.array(verts))
t_array=np.array([t.dot(x) for x in b]) #apply transform to all points
return t_array
def plot_3d_tern(df,c='1'): #use function "get_cartesian_array_from_barycentric" to plot the scatter points
#args are b=dataframe to plot and c=scatter point color
bary_arr=df.values
cartesian_points=get_cartesian_array_from_barycentric(bary_arr)
ax.scatter(cartesian_points[:,0],cartesian_points[:,1],cartesian_points[:,2],c=c)
#Create Dataset 1
np.random.seed(123)
c1=np.random.normal(8,2.5,20)
c2=np.random.normal(8,2.5,20)
c3=np.random.normal(8,2.5,20)
c4=[100-x for x in c1+c2+c3] #make sur ecomponents sum to 100
#df unecessary but that is the format of my real data
df1=pd.DataFrame(data=[c1,c2,c3,c4],index=['c1','c2','c3','c4']).T
df1=df1/100
#Create Dataset 2
np.random.seed(1234)
c1=np.random.normal(16,2.5,20)
c2=np.random.normal(16,2.5,20)
c3=np.random.normal(16,2.5,20)
c4=[100-x for x in c1+c2+c3]
df2=pd.DataFrame(data=[c1,c2,c3,c4],index=['c1','c2','c3','c4']).T
df2=df2/100
#Create Dataset 3
np.random.seed(12345)
c1=np.random.normal(25,2.5,20)
c2=np.random.normal(25,2.5,20)
c3=np.random.normal(25,2.5,20)
c4=[100-x for x in c1+c2+c3]
df3=pd.DataFrame(data=[c1,c2,c3,c4],index=['c1','c2','c3','c4']).T
df3=df3/100
fig = plt.figure()
ax = Axes3D(fig) #Create a 3D plot in most recent version of matplot
plot_ax() #call function to draw tetrahedral outline
label_points() #label the vertices
plot_3d_tern(df1,'b') #call function to plot df1
plot_3d_tern(df2,'r') #...plot df2
plot_3d_tern(df3,'g') #...
关于python - 如何在 R 或 Python 中制作 3d(4 变量)三元(金字塔)图?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/57467943/