如何在3D中绘制2个向量

Question

import numpy as np
import matplotlib
matplotlib.rcParams['backend'] = "Qt4Agg"
import matplotlib.pyplot as plt
import seaborn as sns 
from mpl_toolkits.mplot3d import Axes3D


fig = plt.figure()
ax = fig.gca(projection='3d')

%matplotlib inline
p=np.array([1,-3,5])
q=np.array([3,2,6])
ax.quiver(p,q)
ax.legend()

plt.show()

I'm trying to plot the 2 vectors p and q in 3D. I keep getting this error message

ValueError: need at least one array to concatenate

Not sure what I need to do to get this plot to show.

Answer 1

quiver is for plotting a vector field (for example, the velocity field).

You can use plot to plot line between 0 and q (or p)

ax.plot(*np.vstack([[0,0,0],p]).T)
ax.plot(*np.vstack([[0,0,0],q]).T)

You can use quiver to add arrows at the end of the lines.

ax.quiver(*q,*q)
ax.quiver(*p,*p)