Not able to plot real time graph using matplotlib - python

I have written the following code with the help of online search. My intention here is to get a real time graph with time on x axis and some randomly generated value on y axis
import matplotlib.pyplot as plt
import matplotlib.animation as animation
import time
import numpy as np
fig = plt.figure()
ax1 = fig.add_subplot(1,1,1)
def animate(i):
xar = []
yar = []
x,y = time.time(), np.random.rand()
xar.append(x)
yar.append(y)
ax1.clear()
ax1.plot(xar,yar)
ani = animation.FuncAnimation(fig, animate, interval=1000)
plt.show()
With the above code I just see the range of y axis changing continuously and the graph will not appear in the figure.

The problem is that you never update xvar and yvar. You can do that by moving the definitions of the lists outside the definition of animate.
import matplotlib.pyplot as plt
import matplotlib.animation as animation
import time
import numpy as np
fig = plt.figure()
ax1 = fig.add_subplot(1,1,1)
xar = []
yar = []
def animate(i):
x,y = time.time(), np.random.rand()
xar.append(x)
yar.append(y)
ax1.clear()
ax1.plot(xar,yar)
ani = animation.FuncAnimation(fig, animate, interval=1000)
plt.show()

Related

matlibplot real-time plotting doesn't work

I have created the script below for real-time data plotting. But the plot which shows up is empty. Could you tell me what's the case?
import matplotlib.pyplot as plt
import matplotlib.animation as animation
from matplotlib import style
from itertools import count
import random
style.use('fivethirtyeight')
fig = plt.figure()
axl = fig.add_subplot(1,1,1)
x_vals = []
y_vals = []
index = count()
def animate(i):
x_vals.append(next(index))
y_vals.append(random.randint(0, 5))
axl.clear()
axl.plot(x_vals,y_vals)
ani = animation.FuncAnimation(fig, animate, interval=1000)
plt.show()
I'm using python 3.8, matlibplot 3.1.2 and PyCharm as IDE.

Extra Figure in Matplotlib Animation using Smopy

I'm trying to create an animated map plot using smopy and matplotlib in jupyter, but when I run the code I get two figures instead of one. The first figure is shown above the map and empty. Can anyone tell me how to fix this so that only the animation is drawn?
import smopy
import matplotlib.animation as animation
n= 1000
%matplotlib notebook
def update(curr):
if curr == n-100:
a.event_source.stop()
lons = crime_df.X[curr:curr+100]
lats = crime_df.Y[curr:curr+100]
x,y = map.to_pixels(lats,lons)
ax.scatter(x, y, c='r', alpha=0.7, s=200)
plt.title(curr)
fig = plt.figure()
ax = smopy.Map((37.6624,-122.5168,37.8231,-122.3589), z=12)
ax = ax.show_mpl(figsize=(8,8))
a = animation.FuncAnimation(fig, update, interval=100)
You should not create an additional figure, if that is undersired: Leave out plt.figure().
import smopy
import matplotlib.pyplot as plt
import matplotlib.animation as animation
n= 1000
%matplotlib notebook
def update(curr):
if curr == n-100:
a.event_source.stop()
lons = crime_df.X[curr:curr+100]
lats = crime_df.Y[curr:curr+100]
x,y = map.to_pixels(lats,lons)
ax.scatter(x, y, c='r', alpha=0.7, s=200)
plt.title(curr)
m = smopy.Map((37.6624,-122.5168,37.8231,-122.3589), z=12)
ax = m.show_mpl(figsize=(8,8))
a = animation.FuncAnimation(ax.figure, update, interval=100)
Alternatively create the figure beforehands,
fig, ax = plt.subplots(figsize=(8,8))
m = smopy.Map((37.6624,-122.5168,37.8231,-122.3589), z=12)
m.show_mpl(ax = ax)
a = animation.FuncAnimation(fig, update, interval=100)

Syntax for plotting three points' movement using FuncAnimation

My code:
fig = plt.figure()
ax = fig.add_subplot(111, projection='3d')
def animate(i):
ax.set_data(ax.scatter(ptx1, pty1, ptz1, c='red'),
ax.scatter(ptx2, pty2, ptz2, c='blue'),
ax.scatter(ptx3, pty3, ptz3, c='green'))
ani = FuncAnimation(fig, animate, frames=10, interval=200)
plt.show()
I'm trying to plot the movement of three points. Each ptx/y/z/1/2/3 is a list of floats giving the coordinates of the point. I'm just not sure how to use FuncAnimation to animate my points. Any help would be greatly appreciated!
Simple example. animate is called many times and everytime you have to use different data to see animation.
import matplotlib.pyplot as plt
from matplotlib.animation import FuncAnimation
import random
# create some random data
ptx1 = [random.randint(0,100) for x in range(20)]
pty1 = [random.randint(0,100) for x in range(20)]
fig = plt.figure()
ax = fig.add_subplot(111)
def animate(i):
# use i-th elements from data
ax.scatter(ptx1[:i], pty1[:i], c='red')
# or add only one element from list
#ax.scatter(ptx1[i], pty1[i], c='red')
ani = FuncAnimation(fig, animate, frames=20, interval=500)
plt.show()

Plot a graph point to point python

I wonder if there is some way to plot a waveform point to point at a certain rate through the matplotlib so that the graph appears slowly in the window. Or another method to graph appears at a certain speed in the window and not all the points simultaneously. I've been tried this but I can only plot a section of points at a time
import numpy as np
import matplotlib.pyplot as plt
import time
x = np.arange(0,5,0.001)
y = np.sin(2*np.pi*x)
ind_i = 0
ind_f = 300
while ind_f <= len(x):
xtemp = x[ind_i:ind_f]
ytemp = y[ind_i:ind_f]
plt.hold(True)
plt.plot(xtemp,ytemp)
plt.show()
time.sleep(1)
ind_i = ind_f
ind_f = ind_f + 300
You can also do this with Matplotlib's FuncAnimation function. Adapting one of the matplotlib examples:
import numpy as np
import matplotlib.pyplot as plt
import matplotlib.animation as animation
x = np.arange(0,5,0.001)
y = np.sin(2*np.pi*x)
def update_line(num, data, line):
line.set_data(data[..., :num])
return line,
fig = plt.figure()
data = np.vstack((x,y))
l, = plt.plot([], [], 'r-')
plt.xlim(0, 5)
plt.ylim(-1, 1)
line_ani = animation.FuncAnimation(fig, update_line, frames=1000,
fargs=(data, l), interval=20, blit=False)
plt.show()

Matplotlib FuncAnimation only draws one frame

I am trying to do an animation using the FuncAnimation module, but my code only produces one frame and then stops. It seems like it doesn't realize what it needs to update. Can you help me what went wrong?
import numpy as np
import matplotlib.pyplot as plt
import matplotlib.animation as animation
x = np.linspace(0,2*np.pi,100)
def animate(i):
PLOT.set_data(x[i], np.sin(x[i]))
print("test")
return PLOT,
fig = plt.figure()
sub = fig.add_subplot(111, xlim=(x[0], x[-1]), ylim=(-1, 1))
PLOT, = sub.plot([],[])
animation.FuncAnimation(fig, animate, frames=len(x), interval=10, blit=True)
plt.show()
import numpy as np
import matplotlib.pyplot as plt
import matplotlib.animation as animation
x = np.linspace(0,2*np.pi,100)
fig = plt.figure()
sub = fig.add_subplot(111, xlim=(x[0], x[-1]), ylim=(-1, 1))
PLOT, = sub.plot([],[])
def animate(i):
PLOT.set_data(x[:i], np.sin(x[:i]))
# print("test")
return PLOT,
ani = animation.FuncAnimation(fig, animate, frames=len(x), interval=10, blit=True)
plt.show()
You need to keep a reference to the animation object around, otherwise it gets garbage collected and it's timer goes away.
There is an open issue to attach a hard-ref to the animation to the underlying Figure object.
As written, your code well only plot a single point which won't be visible, I changed it a bit to draw up to current index

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