Interactive plot in Jupyter notebook

Question

I am trying to get 'realtime' ploting in Jupyter notebook. The example can be found here. Here is the code:

%matplotlib notebook

import numpy as np
import matplotlib.pyplot as pl

from random import randint
from time import sleep

from ipywidgets import FloatProgress
from IPython import display

siz = 10
dat = np.zeros((siz, siz))

fig = pl.figure()
axe = fig.add_subplot(111)
img = axe.imshow(dat)

num = 1000

prgBar = FloatProgress(min=0, max=num-1)
display.display(prgBar)

for i in range(num):
    prgBar.value = i
    pos = (randint(0, siz-1), randint(0, siz-1))
    dat[pos] += 1
    img.set_data(dat)
    img.autoscale()
    #sleep(0.01)

What I am aiming for is to see how the plot is changing with each itteration. I also tried set the interactive mod on by pl.ion(), changing backent to inline, calling pl.draw(), but non of it was working. BTW, the progressbar is working just fine...

Thanks Radek

Answer 1

The following code should do the trick:

import numpy as np
import matplotlib.pyplot as plt

from random import randint
from time import sleep

from ipywidgets import FloatProgress
from IPython.display import display, clear_output

siz = 10
dat = np.zeros((siz, siz))

fig = plt.figure()
axe = fig.add_subplot(111)
img = axe.imshow(dat)

num = 1000

prgBar = FloatProgress(min=0, max=num-1)
display(prgBar)

for i in range(num):
    clear_output(wait = True)
    prgBar.value = i
    pos = (randint(0, siz-1), randint(0, siz-1))
    dat[pos] += 1
    img.set_data(dat)
    img.autoscale()
    display(fig)

I changed the for loop creating the image on each step and also imported clear_output to clean the cell output on each step.