We will now discuss the features Matplotlib provides to create contour plots and display images.
Contour lines (also known as level lines or isolines) for a function of two variables are curves where the function has constant values. Mathematically speaking, it's a graph image that shows:
f(x, y) = L
with L constant. Contour lines often have specific names beginning with iso- (from Greek, meaning equal) according to the nature of the variables being mapped.
There are a lot of applications of contour lines in several fields such as meteorology (for temperature, pressure, rain precipitation, wind speed), geography, oceanography, cartography (elevation and depth), magnetism, engineering, social sciences, ...