How to draw simple 3d axis in python3? - python-3.x

I would like to have names of axes as in the figure.

This could be a good starter. Try experiment with it.
import matplotlib.pyplot as plt
from mpl_toolkits.mplot3d import Axes3D
import numpy as np
fig = plt.figure(figsize=[8,8])
ax = fig.gca(projection = '3d')
# some settings
vleng = 4
aleng = vleng/3.
p = np.array([vleng, 0, 0])
q = np.array([0, vleng, 0])
r = np.array([0, 0, vleng])
ax.plot(*np.vstack([[0,0,0], p]).T, color='b')
ax.plot(*np.vstack([[0,0,0], q]).T, color='g')
ax.plot(*np.vstack([[0,0,0], r]).T, color='r')
# plotting arrow at terminal of the lines
ax.quiver(vleng, 0, 0, aleng, 0, 0, \
length=0.5, arrow_length_ratio=0.5, color='r')
ax.quiver(0, vleng, 0, 0, aleng, 0, \
length=0.5, arrow_length_ratio=0.5, color='m')
ax.quiver(0, 0, vleng, 0, 0, aleng, \
length=0.5, arrow_length_ratio=0.5, color='k')
ax.text3D(vleng+1.5, 0, 0, 'X')
ax.text3D(0, vleng+1.0, 0, 'y')
ax.text3D(0, 0, vleng+1.0, 'z')
ax.azim = 35 # y rotation (default=270)
ax.elev = 20 # x rotation (default=0)
ax.dist = 15 # zoom (define perspective)
ax.set_axis_off( ) # hide all grid
ax.set_aspect('equal')
# plot poly1
ax.plot3D( [3.5, 0.25, 2, 3.5], [1, 0.25, 2.5, 1], [1.9, 3.2, 3.8, 1.9], label = 'one line', color='pink' )
# projection of poly1 on xy-plane
ax.plot3D( [3.5, 0.25, 2, 3.5], [1, 0.25, 2.5, 1], [0, 0, 0, 0], label = 'one line', color='gray' )
#ax.legend()
plt.show()

Related

Changing the grid properties of insets in matplotlib

This is a follow up to my question posted here. A network diagram is added as an inset in matplotlib figure.
import networkx as nx
import matplotlib.pyplot as plt
G = nx.gnm_random_graph(n=10, m=15, seed=1)
nxpos = nx.spring_layout(G, dim=3, seed=1)
nxpts = [nxpos[pt] for pt in sorted(nxpos)]
nx_lines = [(nxpts[i], nxpts[j]) for i, j in G.edges()]
# node values
values = [[1, 0, 0, 0, 0, 0, 0, 0, 0, 0],
[30, 80, 10, 79, 70, 60, 75, 78, 65, 10],
[1, .30, .10, .79, .70, .60, .75, .78, .65, .90]]
time = [0.0, 0.1, 0.2] # in seconds
fig, ax = plt.subplots()
ax.plot(
[1, 2, 3], [1, 2, 3],
'go-',
label='line 1',
linewidth=2
)
from mpl_toolkits.mplot3d import (Axes3D)
from matplotlib.transforms import Bbox
rect = [.6, 0, .5, .5]
bbox = Bbox.from_bounds(*rect)
inax = fig.add_axes(bbox, projection = '3d')
# inax.axis('off')
# set angle
angle = 25
inax.view_init(10, angle)
# hide axes, make transparent
# inax.set_facecolor('none')
inax.grid('off')
import numpy as np
# plot 3d
seen = set()
for i, j in G.edges():
x = np.stack((nxpos[i], nxpos[j]))
inax.plot(*x.T, color = 'k')
if i not in seen:
inax.scatter(*x[0], color = 'skyblue')
seen.add(i)
if j not in seen:
inax.scatter(*x[1], color = "skyblue")
seen.add(j)
fig.show()
I would like to change the grid properties i.e set the grid color to red and change line width. I tried inax.grid('on', color='r') but this doesn't change the color. Suggestions on how to change the settings will be really helpful.
You can do it like this:
inax.w_xaxis._axinfo.update({'grid' : {'color': 'red', 'linewidth': 0.8, 'linestyle': '-'}})
inax.w_yaxis._axinfo.update({'grid' : {'color': 'red', 'linewidth': 0.8, 'linestyle': '-'}})
inax.w_zaxis._axinfo.update({'grid' : {'color': 'red', 'linewidth': 0.8, 'linestyle': '-'}})
Output:

Adding image generated from another library as inset in matplotlib

I've generated a network figure using vedo library and I'm trying to add this as an inset to a figure generated in matplotlib
import networkx as nx
import matplotlib.pyplot as plt
from vedo import *
from matplotlib.offsetbox import OffsetImage, AnnotationBbox
G = nx.gnm_random_graph(n=10, m=15, seed=1)
nxpos = nx.spring_layout(G, dim=3, seed=1)
nxpts = [nxpos[pt] for pt in sorted(nxpos)]
nx_lines = [(nxpts[i], nxpts[j]) for i, j in G.edges()]
pts = Points(nxpts, r=12)
edg = Lines(nx_lines).lw(2)
# node values
values = [[1, 0, 0, 0, 0, 0, 0, 0, 0, 0],
[30, 80, 10, 79, 70, 60, 75, 78, 65, 10],
[1, .30, .10, .79, .70, .60, .75, .78, .65, .90]]
time = [0.0, 0.1, 0.2] # in seconds
vplt = Plotter(N=1)
pts1 = pts.cmap('Blues', values[0])
vplt.show(
pts1, edg,
axes=False,
bg='white',
at=0,
interactive=False,
zoom=1.5
).screenshot("network.png")
ax = plt.subplot(111)
ax.plot(
[1, 2, 3], [1, 2, 3],
'go-',
label='line 1',
linewidth=2
)
arr_img = vplt.screenshot(returnNumpy=True, scale=1)
im = OffsetImage(arr_img, zoom=0.25)
ab = AnnotationBbox(im, (1, 0), xycoords='axes fraction', box_alignment=(1.1, -0.1), frameon=False)
ax.add_artist(ab)
plt.show()
ax.figure.savefig(
"output.svg",
transparent=True,
dpi=600,
bbox_inches="tight"
)
There resolution of the image in the inset is too low. Suggestions on how to add the inset without loss of resolution will be really helpful.
EDIT:
The answer posted below works for adding a 2D network, but I am still looking for ways that will be useful for adding a 3D network in the inset.
I am not familiar with vedo but the general procedure would be to create an inset_axis and plot the image with imshow. However, your code is using networkx which has matplotlib bindings and you can directly do this without vedo
EDIT: code edited for 3d plotting
import networkx as nx
import matplotlib.pyplot as plt
G = nx.gnm_random_graph(n=10, m=15, seed=1)
nxpos = nx.spring_layout(G, dim=3, seed=1)
nxpts = [nxpos[pt] for pt in sorted(nxpos)]
nx_lines = [(nxpts[i], nxpts[j]) for i, j in G.edges()]
# node values
values = [[1, 0, 0, 0, 0, 0, 0, 0, 0, 0],
[30, 80, 10, 79, 70, 60, 75, 78, 65, 10],
[1, .30, .10, .79, .70, .60, .75, .78, .65, .90]]
time = [0.0, 0.1, 0.2] # in seconds
fig, ax = plt.subplots()
ax.plot(
[1, 2, 3], [1, 2, 3],
'go-',
label='line 1',
linewidth=2
)
from mpl_toolkits.mplot3d import (Axes3D)
from matplotlib.transforms import Bbox
rect = [.6, 0, .5, .5]
bbox = Bbox.from_bounds(*rect)
inax = fig.add_axes(bbox, projection = '3d')
# inax = add_inset_axes(,
# ax_target = ax,
# fig = fig, projection = '3d')
# inax.axis('off')
# set angle
angle = 25
inax.view_init(10, angle)
# hide axes, make transparent
# inax.set_facecolor('none')
# inax.grid('off')
import numpy as np
# plot 3d
seen = set()
for i, j in G.edges():
x = np.stack((nxpos[i], nxpos[j]))
inax.plot(*x.T, color = 'k')
if i not in seen:
inax.scatter(*x[0], color = 'skyblue')
seen.add(i)
if j not in seen:
inax.scatter(*x[1], color = "skyblue")
seen.add(j)
fig.show()

How to improve cone - make the bases more like a circle?

I have a code for plotting a cone with some text and arrows like axes. How to change this code to get the bases of the cone looking like circles? Is the problem in the settings of margins? Or is it necessary to define circles in another way?
import numpy as np
import matplotlib.pyplot as plt
from mpl_toolkits import mplot3d
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)
nn = 400 # number of points along circle's perimeter
theta = np.linspace(0, 2*np.pi, nn)
rho = np.ones(nn)
# (x,y) represents points on circle's perimeter
x = np.ravel(rho*np.cos(theta))
y = np.ravel(rho*np.sin(theta))
fig, ax = plt.subplots()
plt.rcParams["figure.figsize"] = [5, 5]
figsize = (5, 5)
ax = plt.axes(projection='3d') # set the axes for 3D plot
ax.azim = -88 # y rotation (default=270)
ax.elev = 13 # x rotation (default=0)
# Low, high values of z for plotting 2 circles at different elevation
loz, hiz = -15, 15
# Plot two circles
ax.plot(x, y, hiz)
ax.plot(x, y, loz)
# Set some indices to get proper (x,y) for line plotting
lo1,hi1 = 15, 15+nn//2
lo2,hi2 = lo1+nn//2-27, hi1-nn//2-27
# Plot 3d lines using coordinates of selected points
ax.plot([x[lo1], x[hi1]], [y[lo1], y[hi1]], [loz, hiz])
ax.plot([x[lo2], x[hi2]], [y[lo2], y[hi2]], [loz, hiz])
eps = 0.005
ax.plot([0, 0], [0, 0], [0, 20]) # extend in z direction
ax.plot([0-eps, 0], [0-eps, -5], [0-eps, 0]) # extend in y direction
ax.plot([0, 1.3], [0, 0], [0, 0]) # extend in x direction
ax.plot([0+eps, 0.6], [0+eps, -4], [0+eps, 16]) # v vector
ax.plot([0.63, 0.63], [-4, -4], [16, -0.005]) # vertical projection
ax.plot([0+eps, 0.6], [0+eps, -4], [0+eps, -0.005]) # to the beginning
ax.scatter(0, 0, 20, marker=(3, 0, 0), s=100, clip_on=False)
ax.scatter(0, -5, 0, marker=(3, 0, 43), s=100, clip_on=False)
ax.scatter(1.3, 0, 0, marker=(3, 0, 30), s=100, clip_on=False)
ax.scatter(0.6, -4, 16, marker=(3, 0, 80), s=100, clip_on=False)
ax.scatter(0.6, -4, -0.005, marker=(3, 0, 0), s=100, clip_on=False)
a2 = Arrow3D([0.14, -0.515], [-5.581, 1.358], [14.73, 4.983], mutation_scale=20, arrowstyle="-|>", color="k", connectionstyle="arc3,rad=0.3")
ax.add_artist(a2)
ax.text3D(0.23, -5.23, 23.33, r'$A$')
ax.text3D(1.41, 1.29, -2.7, r'$B$')
ax.text3D(-0.31, 1.46, -12.6, r'$C$')
ax.text3D(0.4, -5.48, 17, r'$D$')
ax.text3D(0.64, 1.57, -9.95, r'$E$')
ax.text3D(-0.2, -5.5, 15.73, r'$F$')
# Hide axes
ax._axis3don = False
# Save the figure (.pdf)
margins = { # vvv margin in inches
"left" : 1 / figsize[0],
"bottom" : -2.45 / figsize[1],
"right" : 1 - 0.5 / figsize[0],
"top" : 1 + 1.8 / figsize[1]
}
fig.subplots_adjust(**margins)
plt.savefig('output.pdf')
plt.show()
From this code I got the following output:
The desired output is bases looking like a circle.
This is the view from above:
It is not a circle but an ellipse.
Desired shape of the cone:

How to plot 3d axes in python3

I ran the following script for plotting 3d axes:
import matplotlib.pyplot as plt
from mpl_toolkits.mplot3d import Axes3D
import numpy as np
fig = plt.figure(figsize=[10,3])
ax = fig.gca(projection = '3d')
# some settings
vleng = 5
aleng = vleng/3.
p = np.array([vleng, 0, 0])
q = np.array([0, vleng, 0])
r = np.array([0, 0, vleng])
ax.plot(*np.vstack([[0,0,0], p]).T, color='black')
ax.plot(*np.vstack([[0,0,0], q]).T, color='black')
ax.plot(*np.vstack([[0,0,0], r]).T, color='black')
# plotting arrow at terminal of the lines
ax.quiver(vleng, 0, 0, aleng, 0, 0, \
length=0.5, arrow_length_ratio=0.5, color='black')
ax.quiver(0, vleng, 0, 0, aleng, 0, \
length=0.5, arrow_length_ratio=0.5, color='black')
ax.quiver(0, 0, vleng, 0, 0, aleng, \
length=0.5, arrow_length_ratio=0.5, color='black')
ax.text3D(vleng+1.5, 0, 0, 'X')
ax.text3D(0, vleng+1.0, 0, 'y')
ax.text3D(0, 0, vleng+1.0, 'z')
ax.azim = 8 # y rotation (default=270)
ax.elev = 15 # x rotation (default=0)
ax.dist = 10 # zoom (define perspective)
ax.set_axis_off( ) # hide all grid
plt.show()
plt.savefig('axes.pdf')
It gives:
Figure
How to set the length of y-axis? I am not able to set it. I tried several changes in the code, but unsuccessfully.

Use nested circles as legend

I would like to use nested circles as legend in Python in a seaborn scatterplot where I used their size to indicate a quantity.
For now I managed, using the legend's labels and handles, to get two circles for the two extremes. Would you know how I can nest them?
I have in mind something like this:
I tried to draw stacked circles in legend by writing Handlers. Here is the implementation.
This will give the figure like output image and would be modified to what you need.
import matplotlib.pyplot as plt
from matplotlib.lines import Line2D
from matplotlib.collections import PathCollection
from matplotlib.legend_handler import HandlerLine2D, HandlerPathCollection
class HandlerPath(HandlerPathCollection):
"""
Custom Handler for HandlerPathCollection instances.
"""
def create_artists(self, legend, orig_handle,
xdescent, ydescent, width, height, fontsize, trans):
xdata, xdata_marker = self.get_xdata(legend, xdescent, ydescent,
width, height, fontsize)
leglines = []
legline_1 = Line2D([10], [5], marker='o', markerfacecolor='darkred', markersize=10, alpha=0.3)
legline_2 = Line2D([10], [5], marker='o', markerfacecolor='darkred', markersize=20, alpha=0.3)
legline_1.set_color("darkred")
legline_2.set_color("darkred")
leglines.append(legline_1)
leglines.append(legline_2)
return leglines
fig, ax = plt.subplots()
l = ax.plot([0.5, 0, -0.5], [0.5, 0, -0.5], linestyle = '--', color='darkred', marker='o', label="TinyTL")
c = ax.scatter([0.5, 0, -0.5], [0.5, 0, -0.5] , s = 1e3, alpha=0.3, color="darkred")
ax.legend(
l+[c], ["line", "circles"],
handler_map={
Line2D: HandlerLine2D(),
PathCollection: HandlerPath()
},
handlelength=2.5, handleheight=3
)
plt.savefig('test.png')
Hope this helps.
Recently, I want to achieve the same legend of the nested circles. The following is my implementation:
import matplotlib.pyplot as plt
import matplotlib.legend_handler as mhandler
import pandas as pd
# Sample data
data = [[ 0, 2, 0, 0, 0, 0, 0, 0],
[ 0, 0, 0, 0, 2, 0, 0, 0],
[ 0, 0, 0, 0, 0, 0, 2, 0],
[ 2, 0, 6, 0, 0, 6, 0, 0],
[ 2, 2, 2, 2, 3, 0, 0, 2],
[ 8, 0, 8, 0, 0, 0, 0, 0],
[ 6, 6, 6, 2, 0, 0, 0, 0],
[10, 6, 2, 0, 0, 2, 0, 0],
[10, 10, 2, 0, 4, 2, 0, 0],
[ 8, 9, 8, 20, 10, 0, 8, 2]]
df = pd.DataFrame(data).reset_index().melt(id_vars=['index'])
fig, ax = plt.subplots(figsize=(7, 7), dpi=100)
bubbles = ax.scatter(
df['index'], df['variable'],
s=df['value']*70, # So that the marker is larger
marker='o',
c='#FFB24D', edgecolor='#FF6A1C', lw=1.5,
)
# Set markers' properties before they are used as the legend handles.
def set_marker_color(handle, orig_handle):
handle.update_from(orig_handle)
handle.set_facecolor('w')
handle.set_edgecolor('k')
legend = ax.legend([bubbles], ['value'], handletextpad=2,
scatterpoints=3, # Choose three marker points for a legend entry
handler_map={
type(bubbles):
mhandler.HandlerPathCollection(
sizes=[30*70, 10*70, 2*70], # Choose the corresponding size.
marker_pad=1, # So that all points have the same x coordinate.
yoffsets=[0, -1.2, -2.1], # Offset in the y direction to get the expected layout.
update_func=set_marker_color)}, # If not, the legend handles will be same as the original handles.
frameon=False,
loc='lower left',
bbox_to_anchor=(0.01, 1.05))
After that, you can use ax.text or ax.annotate to add some labels in the legend handles.
However, I haven't figured out any way to add the number labels automatically, or to get the marker_pad and yoffsets automatically.
I hope this can be a start, and someone can find a more generic way to achieve this kind of legend.

Resources