Reputation:
I am trying to plot a 3d Cartesian coordinate system with matplotlib, center the origin, 3 direction with arrows, some thing like this
I have already plotted a 2d version with this code, based on this post
def build_cartesian_plane(max_quadrant_range):
""" The quadrant range controls the range of the quadrants"""
l = []
zeros = []
f, ax = plt.subplots(figsize=(5,5))
plt.grid(True, color='grey', zorder=0,alpha=.5)
head_width = float(0.05) * max_quadrant_range
head_length = float(0.1) * max_quadrant_range
ax.arrow(0, 0, max_quadrant_range, 0, head_width=head_width, head_length=head_length, fc='k', ec='k',zorder=100)
ax.arrow(0, 0, 0, max_quadrant_range, head_width=head_width, head_length=head_length, fc='k', ec='k', zorder=100)
counter_dash_width = max_quadrant_range * 0.02
dividers = [0,.1,.2,.3,.4, .5, .6, .7, .8, .9, 1]
ax.spines['top'].set_color('none')
ax.spines['bottom'].set_position('zero')
ax.spines['left'].set_position('zero')
ax.spines['right'].set_color('none')
for i in dividers:
ax.plot([-counter_dash_width, counter_dash_width], [i*max_quadrant_range, i*max_quadrant_range], color='k')
ax.plot([i * max_quadrant_range, i*max_quadrant_range], [-counter_dash_width, counter_dash_width], color='k')
ax.plot([-counter_dash_width, counter_dash_width], [-i * max_quadrant_range, -i * max_quadrant_range], color='k')
ax.plot([-i * max_quadrant_range, -i * max_quadrant_range], [-counter_dash_width, counter_dash_width], color='k')
l.append(i * max_quadrant_range)
l.append(-i * max_quadrant_range)
zeros.append(0)
zeros.append(0)
build_cartesian_plane(10)
plt.show()
It seems that ax.arrow
does not support 3d to do this, so, I've to use quiver to plot a simple 3d version.
ax.quiver(0, 0, 0, 0, 3, 0,
arrow_length_ratio=0.1)
ax.quiver(0, 0, 0, 3, 0, 0,
arrow_length_ratio=0.1)
ax.quiver(0, 0, 0, 0, 0, 3,
arrow_length_ratio=0.1)
limt = 2
ax.set_xlim([-limt, limt])
ax.set_ylim([-limt, limt])
ax.set_zlim([-limt, limt])
and got this
I am not familiar with quiver, so I am not sure is it feasible to plot a 3d Cartesian coordinate system with matplotlib.
Any hint would be appreciated.
Upvotes: 8
Views: 15231
Reputation: 306
For an updated version with do_3d_projection
implemented, have a look at: https://gist.github.com/WetHat/1d6cd0f7309535311a539b42cccca89c
Upvotes: 0
Reputation: 391
I found two useful links and put them together. Maybe this is what you are looking for: For the arrows: Drawing a righthand coordinate system in mplot3d and for the 3D cube: python : plotting a wireframe 3D cuboid Have a look at the output first:
import matplotlib as mpl
from mpl_toolkits.mplot3d import Axes3D
import numpy as np
import matplotlib.pyplot as plt
from matplotlib.patches import FancyArrowPatch
from mpl_toolkits.mplot3d import proj3d
class Arrow3D(FancyArrowPatch):
def __init__(self, xs, ys, zs, *args, **kwargs):
FancyArrowPatch.__init__(self, (0, 0), (0, 0), *args, **kwargs)
self._verts3d = xs, ys, zs
def draw(self, renderer):
xs3d, ys3d, zs3d = self._verts3d
xs, ys, zs = proj3d.proj_transform(xs3d, ys3d, zs3d, renderer.M)
self.set_positions((xs[0], ys[0]), (xs[1], ys[1]))
FancyArrowPatch.draw(self, renderer)
def cuboid_data(center, size):
# suppose axis direction: x: to left; y: to inside; z: to upper
# get the (left, outside, bottom) point
o = [a - b / 2 for a, b in zip(center, size)]
# get the length, width, and height
l, w, h = size
x = np.array([[o[0], o[0] + l, o[0] + l, o[0], o[0]], # x coordinate of points in bottom surface
[o[0], o[0] + l, o[0] + l, o[0], o[0]], # x coordinate of points in upper surface
[o[0], o[0] + l, o[0] + l, o[0], o[0]], # x coordinate of points in outside surface
[o[0], o[0] + l, o[0] + l, o[0], o[0]]]) # x coordinate of points in inside surface
y = np.array([[o[1], o[1], o[1] + w, o[1] + w, o[1]], # y coordinate of points in bottom surface
[o[1], o[1], o[1] + w, o[1] + w, o[1]], # y coordinate of points in upper surface
[o[1], o[1], o[1], o[1], o[1]], # y coordinate of points in outside surface
[o[1] + w, o[1] + w, o[1] + w, o[1] + w, o[1] + w]]) # y coordinate of points in inside surface
z = np.array([[o[2], o[2], o[2], o[2], o[2]], # z coordinate of points in bottom surface
[o[2] + h, o[2] + h, o[2] + h, o[2] + h, o[2] + h], # z coordinate of points in upper surface
[o[2], o[2], o[2] + h, o[2] + h, o[2]], # z coordinate of points in outside surface
[o[2], o[2], o[2] + h, o[2] + h, o[2]]]) # z coordinate of points in inside surface
return x, y, z
if __name__ == '__main__':
center = [0, 0, 0]
length = 1
width = 1
height = 1
fig = plt.figure()
ax1 = fig.add_subplot(111, projection='3d')
X, Y, Z = cuboid_data(center, (length, width, height))
ax1.plot_surface(X, Y, Z, color='b', rstride=1, cstride=1, alpha=0.1)
ax1.set_xlabel('X')
ax1.set_xlim(-1, 1)
ax1.set_ylabel('Y')
ax1.set_ylim(-1, 1)
ax1.set_zlabel('Z')
ax1.set_zlim(-1, 1)
# Here we create the arrows:
arrow_prop_dict = dict(mutation_scale=20, arrowstyle='->', shrinkA=0, shrinkB=0)
a = Arrow3D([0, 1], [0, 0], [0, 0], **arrow_prop_dict, color='r')
ax1.add_artist(a)
a = Arrow3D([0, 0], [0, 1], [0, 0], **arrow_prop_dict, color='b')
ax1.add_artist(a)
a = Arrow3D([0, 0], [0, 0], [0, 1], **arrow_prop_dict, color='g')
ax1.add_artist(a)
# Give them a name:
ax1.text(0.0, 0.0, -0.1, r'$0$')
ax1.text(1.1, 0, 0, r'$x$')
ax1.text(0, 1.1, 0, r'$y$')
ax1.text(0, 0, 1.1, r'$z$')
plt.show()
Hope thats helpful. I also need nice arrows, so please post if you find something nicer ;)
Upvotes: 11