Python – Matplotlib: Annotating a 3D scatter plot

matplotlibplotpython

I'm trying to generate a 3D scatter plot using Matplotlib. I would like to annotate individual points like the 2D case here:
Matplotlib: How to put individual tags for a scatter plot.

I've tried to use this function and consulted the Matplotlib docoment but found it seems that the library does not support 3D annotation. Does anyone know how to do this?

Thanks!

Best Answer

Maybe easier via ax.text(...):

from matplotlib import pyplot
from mpl_toolkits.mplot3d import Axes3D
from numpy.random import rand
from pylab import figure

 
m=rand(3,3) # m is an array of (x,y,z) coordinate triplets
 
fig = figure()
ax = fig.add_subplot(projection='3d')

for i in range(len(m)): #plot each point + it's index as text above
    ax.scatter(m[i,0],m[i,1],m[i,2],color='b') 
    ax.text(m[i,0],m[i,1],m[i,2],  '%s' % (str(i)), size=20, zorder=1,  
    color='k') 

ax.set_xlabel('x')
ax.set_ylabel('y')
ax.set_zlabel('z')
pyplot.show()

enter image description here

Related Solutions

Python – How to change the size of figures drawn with Matplotlib

figure tells you the call signature:

from matplotlib.pyplot import figure

figure(figsize=(8, 6), dpi=80)

figure(figsize=(1,1)) would create an inch-by-inch image, which would be 80-by-80 pixels unless you also give a different dpi argument.

Python – Generate a heatmap in MatPlotLib using a scatter data set

If you don't want hexagons, you can use numpy's histogram2d function:

import numpy as np
import numpy.random
import matplotlib.pyplot as plt

# Generate some test data
x = np.random.randn(8873)
y = np.random.randn(8873)

heatmap, xedges, yedges = np.histogram2d(x, y, bins=50)
extent = [xedges[0], xedges[-1], yedges[0], yedges[-1]]

plt.clf()
plt.imshow(heatmap.T, extent=extent, origin='lower')
plt.show()

This makes a 50x50 heatmap. If you want, say, 512x384, you can put bins=(512, 384) in the call to histogram2d.

Example: Matplotlib heat map example

Best Answer

Related Solutions

Python – How to change the size of figures drawn with Matplotlib

Python – Generate a heatmap in MatPlotLib using a scatter data set

Related Topic