Using matplotlib.pyplot.draw(): It is used to update a figure that has been changed. It will redraw the current figure.
Before this we use figure.ion() function to run a GUI event loop. Without using figure.ion() we may not be able to see the GUI plot.
In the given example firstly we are importing all the necessary libraries that we are going to use. And then creating X and Y. X holds the values from 0 to 10 which evenly spaced into 100 values. e.g. we are creating values from 2 to 3 with evenly spaced 5 values (np.linspace(2, 3, 5)) It should output like these 5 values from 2 to 3 evenly spaced array([2 , 2.25, 2.5 , 2.75, 3 ]). After that we are initializing GUI using plt.ion() function, now we have to create a subplot, so we can plot X and Y values. After that we are running a for loop up to some iterations and creating a new_y values which hold our updating value then we are updating the values of X and Y using set_xdata() and set_ydata(). And canvas.draw() will plot the updated values and canvas.flush_events() holds the GUI event till the UI events have been processed. This will run till the loop ends and values will be updated continuously.
Here, figure.canvas.flush_events() is used to clear the old figure before plotting the updated figure.
Example 2: In this example code, we are updating the value of y in a loop using set_xdata() and redrawing the figure every time using canvas.draw().
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