Draw filled plots in python

Matplotlib fill function can fill a polygon given the coordinates of its vertices. See the first example in the following link.

https://matplotlib.org/gallery/lines_bars_and_markers/fill.html

This method can be extended to draw filled curves or shade the area under a curve. For example, if we want to shade the area under a normal distribution up to the z-score -1.4 like this

then we will first generate a list of (x,y) coordinate pairs along the curve of the distribution from x=-4 to x=-1.4 using y = Exp(-x^2/2)/√ (2π).

y-values are generated using the scipy function norm() which returns the value of the Gaussian Exp(-x^2/2)/√ (2π). This will generate (x,y) pairs along the curve of the Gaussian. However, we will need to add the (-1.4,0) coordinate so that the curve closes. 

from scipy.stats import norm
import matplotlib.pyplot as plt
import numpy as np

interval = 0.1

x = np.arange(-4, 4, interval)
y = norm.pdf(x)

# z-score
z = -1.4

# we want to shade from -inf to z or rather the interval [-x_min, z]
# generate x-coordinates: [-x_min,z]
xarea = np.arange(-4, z, interval) 
# generate y-coordinates
yarea = norm.pdf(xarea)  
# need to add the point (x,y): (z, 0) so that 
# polygon fills all the way to the x-axis
# append x=z-score
xarea = np.append(xarea, xarea[-1]) 
# append y=0
yarea = np.append(yarea, 0 )

plt.plot(x, y)

plt.fill(xarea, yarea)

plt.text(-1.4 , 0 , '-1.4' , {'color':'r'})

plt.show()

Maximize plots from within code

# show plot in a maximized window
mng = plt.get_current_fig_manager()
mng.full_screen_toggle()

References
https://matplotlib.org/gallery/text_labels_and_annotations/usetex_demo.html#sphx-glr-gallery-text-labels-and-annotations-usetex-demo-py