带有色度图和图例的Python 3D散点图 [英] 3D scatterplots in Python with hue colormap and legend

问题描述

我一直在用seaborn搜索python中的3D图，但没有看到.我想 3D 绘制我最初使用 seaborn pairplot 绘制的数据集.谁能帮我解决这两个问题:

1. 我无法获得与 sns pairplot 相同的调色板，例如如何从图2获取调色板并将其应用于图1上的点?
2. 图例不符合情节或在pairplot上显示不那么好，例如当我执行 plt.legend(bbox_to_anchor =(1.05，1)，loc = 2，borderaxespad = 0.，ncol = 4)时，我看到以下错误:anaconda2/lib/python2.7/site-packages/matplotlib/axes/_axes.py:545:UserWarning:找不到带标签的对象.在单个图上使用 label='...' kwarg.warnings.warn("未找到带标签的对象."

提前谢谢！我的参考资料:

#Seaborn 配对图df_3d = pd.DataFrame()df_3d['x'] = xdf_3d['y'] = ydf_3d['z'] = zsns.pairplot(df_3d，色相='x')

解决方案

1. 可以将来自 Seaborn 的调色板从 ListedColorMap 类的实例转换为 Matplotlib 颜色图，该类使用 as_hex() 方法(如

   I have been searching for 3D plots in python with seaborn and haven't seen any. I would like to 3D plot a dataset that I originally plotted using seaborn pairplot. Can anyone help me with these 2 issues:

   1. I am not able to get same color palette as sns pairplot, e.g. how to get the color palette from figure 2 and apply to the points on figure 1?
   2. The legend does not stick to the plot or does not show up as nice on pairplot, e.g. When I do plt.legend(bbox_to_anchor=(1.05, 1), loc=2, borderaxespad=0.,ncol=4) I see the following error: anaconda2/lib/python2.7/site-packages/matplotlib/axes/_axes.py:545: UserWarning: No labelled objects found. Use label='...' kwarg on individual plots. warnings.warn("No labelled objects found. "

   Thanks in advance ! My references: How to make a 3D scatter plot in Python? https://pythonspot.com/3d-scatterplot/ https://jakevdp.github.io/PythonDataScienceHandbook/04.12-three-dimensional-plotting.html

   Here's a MWE:

   import re, seaborn as sns, numpy as np, pandas as pd, random
   from pylab import *
   from matplotlib.pyplot import plot, show, draw, figure, cm
   import matplotlib.pyplot as plt
   from mpl_toolkits.mplot3d import Axes3D
   sns.set_style("whitegrid", {'axes.grid' : False})
   
   fig = plt.figure(figsize=(6,6))
   
   ax = Axes3D(fig) # Method 1
   # ax = fig.add_subplot(111, projection='3d') # Method 2
   
   x = np.random.uniform(1,20,size=20)
   y = np.random.uniform(1,100,size=20)
   z = np.random.uniform(1,100,size=20)
   
   
   ax.scatter(x, y, z, c=x, marker='o')
   ax.set_xlabel('X Label')
   ax.set_ylabel('Y Label')
   ax.set_zlabel('Z Label')
   
   plt.show()
   

   #Seaborn pair plot
   df_3d = pd.DataFrame()
   df_3d['x'] = x
   df_3d['y'] = y
   df_3d['z'] = z
   
   sns.pairplot(df_3d, hue='x')
   

   解决方案

   1. The color palette from Seaborn can be turned into a Matplotlib color map from an instance of a ListedColorMap class initialized with the list of colors in the Seaborn palette with the as_hex() method (as proposed in this original answer).

   2. From the Matplotlib documentation, you can generate a legend from a scatter plot with getting the handles and labels of the output of the scatter function.

   The result of the code is shown in the picture below. Note that I generated more data points in order to better see that the colormap is the same. Also, the output of ListedColorMap outputs a color map with transparency variations, so I had to manually set alpha to 1 in the scatter plot.

   import re, seaborn as sns
   import numpy as np
   
   from matplotlib import pyplot as plt
   from mpl_toolkits.mplot3d import Axes3D
   from matplotlib.colors import ListedColormap
   
   # generate data
   n = 200
   x = np.random.uniform(1, 20, size=n)
   y = np.random.uniform(1, 100, size=n)
   z = np.random.uniform(1, 100, size=n)
   
   # axes instance
   fig = plt.figure(figsize=(6,6))
   ax = Axes3D(fig, auto_add_to_figure=False)
   fig.add_axes(ax)
   
   # get colormap from seaborn
   cmap = ListedColormap(sns.color_palette("husl", 256).as_hex())
   
   # plot
   sc = ax.scatter(x, y, z, s=40, c=x, marker='o', cmap=cmap, alpha=1)
   ax.set_xlabel('X Label')
   ax.set_ylabel('Y Label')
   ax.set_zlabel('Z Label')
   
   # legend
   plt.legend(*sc.legend_elements(), bbox_to_anchor=(1.05, 1), loc=2)
   
   # save
   plt.savefig("scatter_hue", bbox_inches='tight')
   

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