Matplotlib Crash Course for Absolute Beginner

Installing Matplotlib 

python -m pip install matplotlib

Concepts Behind Matplotlib

The two main concepts that you have to understand before creating a matplotlib chart or graph are 

1. Figure

2. Axes

Here Figure is the whole main window or the canvas which contain your graphs/plots.

While Axes is the actual plotting area where our graphs are drawn or plotted.

Please note that Axes is different from Axis (x or y).

A single Matplotlib Figure can have multiple Axes as shown below.

No Values have been plotted to the axes.

import matplotlib.pyplot as plt

figure,axes = plt.subplots(nrows=2,ncols=2) # this will create
                                            # 4 axes shown below
plt.show()

You can also have multiple Figures with multiple Axes as shown below.

import matplotlib.pyplot as plt

figure1,axes1 = plt.subplots(nrows=1,ncols=2) #create Figure1 and its axes
figure2,axes2 = plt.subplots(nrows=2,ncols=3) #create Figure2 and its axes

plt.show()

Creating a Simple Line Chart using Matplotlib

Now we will create a simple Line Chart using the Matplotlib Python Library. 

The main steps needed to create a line plot or chart is shown below.

1. Create a list of x and y values which are needed to draw the line

2. Create a Figure and Axes Object using the subplots() method

3. Now Plot the x and y values on the plotting area (axes) using .plot() method

4. call .show() method to show the plots on the screen

You can find the code for doing that below.

#Simple Line chart 

import matplotlib.pyplot as plt


x= [1, 2,3,4, 5,6, 7,8, 9,10,11,12,13,14,15]    #list of values on x axis 
y= [-5,0,5,10,0,20,0,12,7,-1,3, 8,2,0,-16]      #list of values on y axis

figure,axes = plt.subplots() # creates a drawing area for your graph
                             # returns a figure and an axes object
                             # tuple expansion

axes.plot(x,y,'-o') #plot x,y values on axes object.
axes.set_title('Name of the Axes') #set the name of the Axes
axes.grid(True) #show grid lines

figure.canvas.manager.set_window_title('Name of the Window') # Setting the name of the Window/Figure

plt.show()

On running the Code it will create the below window.