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How to do dynamic matplotlib plotting with a fixed pandas dataframe?

I have a dataframe called benchmark_returns and strategy_returns. Both have the same timespan. I want to find a way to plot the datapoints in a nice animation style so that it shows all the points loading in gradually. I am aware that there is a matplotlib.animation.FuncAnimation(), however this typically is only used for a real-time updating of csv files etc but in my case I know all the data I want to use.
I have also tried using the crude plt.pause(0.01) method, however this drastically slows down as the number of points get plotted.
Here is my code so far
x = benchmark_returns.index
y = benchmark_returns['Crypto 30']
y2 = benchmark_returns['Dow Jones 30']
y3 = benchmark_returns['NASDAQ']
y4 = benchmark_returns['S&P 500']
fig, ax = plt.subplots()
line, = ax.plot(x, y, color='k')
line2, = ax.plot(x, y2, color = 'b')
line3, = ax.plot(x, y3, color = 'r')
line4, = ax.plot(x, y4, color = 'g')
def update(num, x, y, y2, y3, y4, line):
line.set_data(x[:num], y[:num])
line2.set_data(x[:num], y2[:num])
line3.set_data(x[:num], y3[:num])
line4.set_data(x[:num], y4[:num])
return line, line2, line3, line4,
ani = animation.FuncAnimation(fig, update, fargs=[x, y, y2, y3, y4, line],
interval = 1, blit = True)
plt.show()

You could try matplotlib.animation.ArtistAnimation. It operates similar to FuncAnimation in that you can specify the frame interval, looping behavior, etc, but all the plotting is done at once, before the animation step. Here is an example
import matplotlib.pyplot as plt
import pandas as pd
import numpy as np
from matplotlib.animation import ArtistAnimation
n = 150
x = np.linspace(0, np.pi*4, n)
df = pd.DataFrame({'cos(x)' : np.cos(x),
'sin(x)' : np.sin(x),
'tan(x)' : np.tan(x),
'sin(cos(x))' : np.sin(np.cos(x))})
fig, axs = plt.subplots(nrows=2, ncols=2, figsize=(10,10))
lines = []
artists = [[]]
for ax, col in zip(axs.flatten(), df.columns.values):
lines.append(ax.plot(df[col])[0])
artists.append(lines.copy())
anim = ArtistAnimation(fig, artists, interval=500, repeat_delay=1000)
The drawback here is that each artist is either drawn or not, i.e. you can't draw only part of a Line2D object without doing clipping. If this is not compatible with your use case then you can try using FuncAnimation with blit=True and chunking the data to be plotted each time as well as using set_data() instead of clearing and redrawing on every iteration. An example of this using the same data from above:
import matplotlib.pyplot as plt
import pandas as pd
import numpy as np
from matplotlib.animation import FuncAnimation
n = 500
nf = 100
x = np.linspace(0, np.pi*4, n)
df = pd.DataFrame({'cos(x)' : np.cos(x),
'sin(x)' : np.sin(x),
'tan(x)' : np.tan(x),
'sin(cos(x))' : np.sin(np.cos(x))})
fig, axs = plt.subplots(2, 2, figsize=(5,5), dpi=50)
lines = []
for ax, col in zip(axs.flatten(), df.columns):
lines.append(ax.plot([], lw=0.5)[0])
ax.set_xlim(x[0] - x[-1]*0.05, x[-1]*1.05)
ax.set_ylim([min(df[col].values)*1.05, max(df[col].values)*1.05])
ax.tick_params(labelbottom=False, bottom=False, left=False, labelleft=False)
plt.subplots_adjust(hspace=0, wspace=0, left=0.02, right=0.98, bottom=0.02, top=0.98)
plt.margins(1, 1)
c = int(n / nf)
def animate(i):
if (i != nf - 1):
for line, col in zip(lines, df.columns):
line.set_data(x[:(i+1)*c], df[col].values[:(i+1)*c])
else:
for line, col in zip(lines, df.columns):
line.set_data(x, df[col].values)
return lines
anim = FuncAnimation(fig, animate, interval=2000/nf, frames=nf, blit=True)
Edit
In response to the comments, here is the implementation of a chunking scheme using the updated code in the question:
x = benchmark_returns.index
y = benchmark_returns['Crypto 30']
y2 = benchmark_returns['Dow Jones 30']
y3 = benchmark_returns['NASDAQ']
y4 = benchmark_returns['S&P 500']
line, = ax.plot(x, y, color='k')
line2, = ax.plot(x, y2, color = 'b')
line3, = ax.plot(x, y3, color = 'r')
line4, = ax.plot(x, y4, color = 'g')
n = len(x) # Total number of rows
c = 50 # Chunk size
def update(num):
end = num * c if num * c < n else n - 1
line.set_data(x[:end], y[:end])
line2.set_data(x[:end], y2[:end])
line3.set_data(x[:end], y3[:end])
line4.set_data(x[:end], y4[:end])
return line, line2, line3, line4,
ani = animation.FuncAnimation(fig, update, interval = c, blit = True)
plt.show()
or, more succinctly
cols = benchmark_returns.columns.values
# or, for only a subset of the columns
# cols = ['Crypto 30', 'Dow Jones 30', 'NASDAQ', 'S&P 500']
colors = ['k', 'b', 'r', 'g']
lines = []
for c, col in zip(cols, colors):
lines.append(ax.plot(benchmark_returns.index, benchmark_returns[col].values, c=c)[0])
n = len(benchmark_returns.index)
c = 50 # Chunk size
def update(num):
end = num * c if num * c < n else n - 1
for line, col in zip(lines, cols):
line.set_data(benchmark_returns.index, benchmark_returns[col].values[:end])
return lines
anim = animation.FuncAnimation(fig, update, interval = c, blit=True)
plt.show()
and if you need it to stop updating after a certain time simply set the frames argument and repeat=False in FuncAnimation().

You can just update the data into the line element like so:
fig = plt.figure()
ax = fig.add_subplot(111)
liner, = ax.plot()
plt.ion()
plt.show()
for i in range(len(benchmark_returns.values)):
liner.set_ydata(benchmark_returns['Crypto 30'][:i])
liner.set_xdata(benchmark_returns.index[:i])
plt.pause(0.01)

Drawing lines between two points with twinaxes

I have followed this example (Drawing lines between two plots in Matplotlib) but am running into problems. I believe it has something to do with the fact that I essentially have two different y points, but am not sure how to amend the code to fix it. I would like the line to start at one point and end at the other point directly below it, as well as plotting for all lines.
fig=plt.figure(figsize=(22,10), dpi=150)
ax1 = fig.add_subplot(1, 1, 1)
ax2 = ax1.twinx()
n = 10
y1 = np.random.random(n)
y2 = np.random.random(n) + 1
x1 = np.arange(n)
ax1.scatter(x1, y1)
ax2.scatter(x1, y2)
i = 1
xy = (x1[i],y1[i])
con = ConnectionPatch(xyA=xy, xyB=xy, coordsA="data", coordsB="data",
axesA=ax1, axesB=ax2, color="red")
ax2.add_artist(con)
ax1.plot(x1[i],y1[i],'g+',markersize=12)
ax2.plot(x1[i],y1[i],'g+',markersize=12)

Just iterate over zipped (x, y1, y2):
import numpy as np
import matplotlib.pyplot as plt
from matplotlib.patches import ConnectionPatch
fig = plt.figure(figsize=(10, 5), dpi=100)
ax1 = fig.add_subplot(1, 1, 1)
ax2 = ax1.twinx()
n = 10
y1 = np.random.random(n)
y2 = np.random.random(n) + 1
x1 = np.arange(n)
# I add some colors blue for left y-axis, red for right y-axis
ax1.scatter(x1, y1, c='b')
ax2.scatter(x1, y2, c='r')
# Now iterate over paired x, and 2 y values:
for xi, y1i, y2i in zip(x1, y1, y2):
con = ConnectionPatch(
xyA=(xi, y1i),
xyB=(xi, y2i),
coordsA="data",
coordsB="data",
axesA=ax1,
axesB=ax2,
color='g',
)
ax1.add_artist(con)
plt.show()
Out:

Continuously change direction of shifting matplotlib animation?

I've been playing with the animation module from matplotlib and I realized I couldn't efficiently make a sine wave loop between two limits (in this case between -180° and 180°).
Like this...
import numpy as np
from matplotlib import pyplot as plt
from matplotlib import animation
fig = plt.figure()
ax = plt.axes(xlim=(0, 0.04), ylim=(-1.5, 1.5))
# initialize moving plots
line1, = ax.plot([], [], linewidth=2, label='sine')
line2, = ax.plot([], [], label='cosine')
ax.legend()
ax.grid()
def animate(i):
step = np.pi/30
# loop by hand...
if i < 30:
phase = i*step
elif 30 <= i < 90:
phase = -i*step
elif 90 <= i < 150:
phase = i*step
elif 150 <= i < 210:
phase = -i*step
else:
phase = i*step
x = np.linspace(0, 0.04, 1000)
y1 = np.sin( 2*np.pi*50*x - phase )
y2 = 0.5*np.cos( 2*np.pi*50*x + phase )
line1.set_data(x, y1)
line2.set_data(x, y2)
print('i:',i) # debug i
return line1, line2
anim = animation.FuncAnimation(fig, animate, interval=250, blit=True)
plt.show()
The reason is because I'm using the i variable, that is used for the frames count and only increases with time. Is there a way to loop indefinitely without writing if conditions until the end of time?
From this answer I found that is posible to refresh the data from the plot, and I've manage to make it loop almost like I wanted.
Adapted example... (workaround not complete)
import matplotlib.pyplot as plt
import numpy as np
def Yvalue(t, phase):
"""Function to plot"""
w = 2*np.pi*50
return np.sin(w*t + phase)
plt.ion() # You probably won't need this if you're embedding things in a tkinter plot...
step = np.pi/30 # steps for phase shifting
t = np.linspace(0, 0.04) # x values
y1 = Yvalue(t, 0) # y values
# starts figure
fig = plt.figure()
ax = plt.axes(xlim=(0, 0.04), ylim=(-1.5, 1.5))
# Returns a tuple of line objects, thus the comma
line1, = ax.plot(t, y1, linewidth=2, label='sine')
# static plot (cosine)
ax.plot(t, np.cos(2*np.pi*50*t), label='cosine static')
ax.legend()
ax.grid()
# initial values
phase = 0
direction = 1 # 1: shifting plot to left; 0: shifting plot to right
UpperLimit = np.pi
LowerLimit = -np.pi
# magic begins...
for something in range(210):
# while 1:
if direction and phase < UpperLimit:
phase += step
direction = 1
else:
phase -= step
direction = 0
# condition that helps to return to left shifting
if phase < LowerLimit:
direction = 1
line1.set_ydata( Yvalue(t, phase) )
fig.canvas.draw()
The problem with is that it doesn't allow me to close the window like it would be with the animation module. Therefore the program must be killed manually when changing the for loop by the while loop.

You would usually not use the animating function itself to calculate its animating parameter. Instead you would provide that parameter as argument to it using the frames argument.
In this case you would want the animating function to take the phase as argument. To create the phase, which is a kind of sawtooth function you can use numpy like
a = np.linspace(0,1, 30, endpoint=False)
phase = np.concatenate((a, 1-a, -a, a-1))*np.pi
Complete example:
import numpy as np
from matplotlib import pyplot as plt
from matplotlib import animation
fig = plt.figure()
ax = plt.axes(xlim=(0, 0.04), ylim=(-1.5, 1.5))
line1, = ax.plot([], [], linewidth=2, label='sine')
line2, = ax.plot([], [], label='cosine')
ax.legend()
ax.grid()
x = np.linspace(0, 0.04, 1000)
a = np.linspace(0,1, 30, endpoint=False)
phase = np.concatenate((a, 1-a, -a, a-1))*np.pi
def animate(phase):
y1 = np.sin( 2*np.pi*50*x - phase )
y2 = 0.5*np.cos( 2*np.pi*50*x + phase )
line1.set_data(x, y1)
line2.set_data(x, y2)
return line1, line2
anim = animation.FuncAnimation(fig, animate, frames=phase, interval=50, blit=True)
plt.show()

I don't know if I understand your problem because I don't see problem to use second method (used in for loop) inside animate
import numpy as np
from matplotlib import pyplot as plt
from matplotlib import animation
fig = plt.figure()
ax = plt.axes(xlim=(0, 0.04), ylim=(-1.5, 1.5))
# initialize moving plots
line1, = ax.plot([], [], linewidth=2, label='sine')
line2, = ax.plot([], [], label='cosine')
ax.legend()
ax.grid()
# -------------------------------------------------
def func1(t, phase):
"""Function to plot"""
w = 2*np.pi*50
return np.sin( w*t + phase)
def func2(t, phase):
"""Function to plot"""
w = 2*np.pi*50
return np.sin( w*t - phase)
# -------------------------------------------------
t = np.linspace(0, 0.04)
step = np.pi/30
UpperLimit = np.pi
LowerLimit = -np.pi
direction = 1
phase = 0
def animate(i):
global direction
global phase
if direction:
phase += step
if phase >= UpperLimit:
direction = 0
else:
phase -= step
if phase < LowerLimit:
direction = 1
line1.set_data(t, func1(t, phase))
line2.set_data(t, func2(t, phase))
return line1, line2
anim = animation.FuncAnimation(fig, animate, interval=250, blit=True)
plt.show()
Or even without variable direction
import numpy as np
from matplotlib import pyplot as plt
from matplotlib import animation
fig = plt.figure()
ax = plt.axes(xlim=(0, 0.04), ylim=(-1.5, 1.5))
# initialize moving plots
line1, = ax.plot([], [], linewidth=2, label='sine')
line2, = ax.plot([], [], label='cosine')
ax.legend()
ax.grid()
# -------------------------------------------------
def func1(t, phase):
"""Function to plot"""
w = 2*np.pi*50
return np.sin( w*t + phase)
def func2(t, phase):
"""Function to plot"""
w = 2*np.pi*50
return np.sin( w*t - phase)
# -------------------------------------------------
t = np.linspace(0, 0.04)
step = np.pi/30
UpperLimit = np.pi
LowerLimit = -np.pi
phase = 0
def animate(i):
global phase
global step
phase += step
if phase >= UpperLimit or phase <= LowerLimit:
step = -step
line1.set_data(t, func1(t, phase))
line2.set_data(t, func2(t, phase))
return line1, line2
anim = animation.FuncAnimation(fig, animate, interval=250, blit=True)
plt.show()

Matplotlib animation patch initialization and rotation. How to do it right?

What are the right ways to initialize and rotate patches in animations? The attached program initializes and rotates patches in an animation, but my solutions are kind of a kludge.
To keep the initialized patches from showing up as static patches, I set alpha=0, but this means that I have to set alpha=1 every time I call the animate function, when I should only have to set this once. I could put in an "if i==0;" statement before the set_alpha(1) call, but that seems inelegant.
To rotate the patches, I use "mag1._angle = i" (see lines 37 & 39) which uses Rectangle's internal attribute _angle. You're not really supposed to do this but I don't see an alternative easy solution. What do the Pythonistas say?
import numpy as np
from matplotlib import pyplot as plt
from matplotlib import animation
fig = plt.figure()
ax = plt.axes(xlim=(-1, 1), ylim=(-1, 1), aspect=1)
ax.set_xticks([])
ax.set_yticks([])
r_in, r_out = 0.25, 0.35
circ_outer = plt.Circle((0, 0), radius=r_out, ec='blue', fc='white', lw=3)
circ_inner = plt.Circle((0, 0), radius=r_in, ec='blue', fc='white', lw=3)
ax.add_patch(circ_outer)
ax.add_patch(circ_inner)
r, w, h = 0.5, 0.07, 0.4
x0, y0 = r, 0.5*h
mag1 = plt.Rectangle((-x0,-y0), width= w, height= h, angle=0, fc='black', alpha=0)
mag2 = plt.Rectangle(( x0, y0), width=-w, height=-h, angle=0, fc='black', alpha=0)
line1, = ax.plot([], [], 'b', zorder=1)
line2, = ax.plot([], [], 'b', zorder=1)
def init():
line1.set_data([], [])
line2.set_data([], [])
ax.add_patch(mag1)
ax.add_patch(mag2)
return mag1, mag2, line1, line2,
def animate(i):
mag1.set_alpha(1)
mag2.set_alpha(1)
thetaMAG = np.radians(i)
x = x0*np.cos(thetaMAG) - y0*np.sin(thetaMAG)
y = x0*np.sin(thetaMAG) + y0*np.cos(thetaMAG)
mag1.xy = (-x, -y)
mag1._angle = i
mag2.xy = (x, y)
mag2._angle = i
j = float(i)/3.0
thetaROT = np.radians(j)
sn = r_in*np.sin(thetaROT)
cs = r_in*np.cos(thetaROT)
line1.set_data([-cs, cs], [-sn, sn])
line2.set_data([sn, -sn], [-cs, cs])
return mag1, mag2, line1, line2,
anim = animation.FuncAnimation(fig, animate, init_func=init, frames=1080,
interval=25, blit=True)
plt.show()

Animation with matplotlib where points are dynamically added to a graph

I've written a simple code which generates random points (x0, y0) between certain values using a while loop. After the coordinates of each point are set, that point is drawn in an empty graph which is showed at the end of the while loop.
However, I would like to set up an animation with matplotlib which would allow me to see the initial graph and the points progressively added to it as the code is calculating them. I've looked for some examples but the ones I found are mainly concerned with waves and so on and I guess I need a slightly different approach.
This is the basic code:
from numpy import *
from pylab import *
import random
figure(figsize=(8,6), dpi=150)
x = np.linspace(-1, 4.5, 250)
h=5
a=0.5
b=4
ylim(-0.5,5.5)
xlim(-1,5.0)
i= 0
while i< 500:
R1 = random.random()
R2 = random.random()
x0 = (b - a)*R1 + a
y0 = h*R2
scatter(x0, y0, 10, color="red")
i = i + 1
show()
Thanks for your help!
EDIT: ANIMATION CODE
import numpy as np
import matplotlib.pyplot as plt
from pylab import *
import matplotlib.animation as animation
import random
fig = plt.figure(figsize=(8,6), dpi=150)
x = np.linspace(-2, 4.5, 250)
h=4
a=1
b=3
hlines(y=h, xmin=1, xmax=3, linewidth=1.5)
vlines(x=a, ymin=0, ymax=4, linewidth=1.5)
vlines(x=b, ymin=0, ymax=4, linewidth=1.5)
ylim(-2.5,10.5)
xlim(-2.5,4.5)
grid()
def data_gen():
i = 0
while i< 1:
R1 = random.random()
R2 = random.random()
x0 = (b - a)*R1 + a
y0 = h*R2
i = i + 1
yield x0, y0
line, = plot([], [], linestyle='none', marker='o', color='r')
ax = gca()
ax.spines['right'].set_color('none')
ax.spines['top'].set_color('none')
ax.xaxis.set_ticks_position('bottom')
ax.spines['bottom'].set_position(('data',0))
ax.yaxis.set_ticks_position('left')
ax.spines['left'].set_position(('data',0))
xdata, ydata = [], []
def run(data):
x0,y0 = data
xdata.append(x0)
ydata.append(y0)
line.set_data(xdata, ydata)
return line,
ani = animation.FuncAnimation(fig, run, data_gen, blit=True, interval=0.5,
repeat=False)
plt.show()

I do not know if this is exactly what you are looking for; in any case, you can generate random points inside the run function and there plot them. You do not need neither blit = True nor clear the axis from one frame to another.
Here is my code:
from pylab import *
from matplotlib.animation import FuncAnimation
import random
fig = plt.figure(figsize=(8,6), dpi=150)
x = np.linspace(-2, 4.5, 250)
h=4
a=1
b=3
hlines(y=h, xmin=a, xmax=b, linewidth=1.5)
vlines(x=a, ymin=0, ymax=h, linewidth=1.5)
vlines(x=b, ymin=0, ymax=h, linewidth=1.5)
ylim(-2.5,10.5)
xlim(-2.5,4.5)
grid()
ax = gca()
ax.spines['right'].set_color('none')
ax.spines['top'].set_color('none')
ax.xaxis.set_ticks_position('bottom')
ax.spines['bottom'].set_position(('data',0))
ax.yaxis.set_ticks_position('left')
ax.spines['left'].set_position(('data',0))
def run(i):
R1 = random.random()
R2 = random.random()
x0 = (b - a)*R1 + a
y0 = h*R2
ax.scatter(x0, y0, 10, color='red')
ani = FuncAnimation(fig = fig, func = run, frames = 500, interval = 10, repeat = False)
plt.show()
which produces this animation:
(I cut this animation to 100 points in order to get a lighter file, less than 2 MB; the code above produces an animation wiht 500 points)