MATLAB Programming/Bonus Chapters/MATLAB Easter Eggs
MATLAB is one of the very few professional software in the market now that included Easter Eggs in their products.
Here are the few known undocumented demo functions: Just type these commands and have a look for yourself:
All of this Easter Eggs were tested on MATLAB R2020a ( in not alphabetical order)
Have fun playing with the known Easter Eggs~ Note: To view the source code, use edit function followed by command name
Working Easter Eggs
editCommand  Description  Picture/Examples 

cruller  Construct a cruller by revolving the eccentric ellipse defined by the function XYCRULL.  
date  Returns date as in ddmmmyyyy format  08Aug2022 
sldemo_fuelsys  Simulations of FaultTolerant Fuel Control System Dashboard  
funtool  A interactive graphing calculator that manipulates functions of a single variable.  
sf_aircraft  Simulate the fuel injection system in aircraft  
sf_newtons_cradle  Simulate Newton's cradle  
teapotdemo 
A demo that uses the famous Newell teapot to demonstrate MATLAB graphics features.  
teapotGeometry  Data generates vertices, faces, and colors that represent the surface of the infamous Utah teapot.  
graf3d  Demonstrate Handle Graphics for surface plots in MATLAB.  
earthmap  Globe to represent the Earth's topography  
soma  Precomputed solutions to Piet Hein's soma cube  
somasols .  Generate complete solutions to the soma cube  
clock  Returns a six element date vector containing the current time and date in decimal form:
[year month day hour minute seconds] 
1.0e+03 *
2.0220 0.0080 0.0070 0.0230 0.0360 0.0192 
taxDemo(income)  Calculate the tax on income.  
logo  Plot the Lshaped membrane logo with MATLAB(R) lighting.  
membrane  Plot a 3D colored surface of MATLAB(R) logos  
spy  This function is actually to use to visualize sparsity pattern.
When no input of argument is given, it will generate a image of the dogs. If typed in version prior to Matlab R2011a, it will show character White Spy from comics Spy vs. Spy 

life  This is MATLAB's simulations of Conway's Game of Life.
Whether cells stay alive, die, or generate new cells depends upon how many of their eight possible neighbors are alive. By using sparse matrices, the calculations required become astonishingly simple. 

truss  Animation of a bending bridge truss. This demo animates 12 natural bending modes of a twodimensional truss.  
vibes  This demonstration solves the wave equation for the vibrations of an Lshaped membrane.  
makevase  Generate and plot a surface of revolution. The bodyofrevolution corresponding to that line is plotted using the SURFL command.  
sf_cdplayer  Simulink model simulate the CD player.  
xpbombs  Shows a game of Minesweeper , There are 13 bombs hidden in the mine field.  
lorenz  Plot the orbit around the Lorenz chaotic attractor.  
travel  This demo animates the solution of the "Traveling Salesman" problem. (Limited to cities inside USA)
The problem is to form a closed circuit of a number of cities while traveling the shortest total distance along the way. 

fifteen  Shows a game of fifteen game puzzles
A sliding puzzle of fifteen squares and sixteen slots. Solve the puzzle by sequentially lining all fifteen squares up, leaving the last square empty. 

bucky  Connectivity graph of the Buckminster Fuller geodesic dome. (shows 60 coordinates)  
sf_spectrum_analyzer  Simulation of measuring the Frequency Response of a System  
census  Shows the extrapolated predicted populations in the United States  
sf_angle_events  Simulate cranking and power output  
ex_guide_timergui  Execute graphic updates at regular intervals  
quivdemo  Superimpose QUIVER on top of a PCOLOR plot with interpolated shading.  
sf_elevator  Simulations of elevators inside 9 storey buildings.  
penny  Shows 3D render of a USA penny  
matlab.ui.internal.toolstrip.Icon.showStandardIcons  Shows allstandard icons  
knot  Compute the parametric representation of tubelike surfaces and displays the tube with SURF.  
spharm2  This example shows how spherical harmonics, which are spherical versions
of Fourier series, can be used to model the free oscillations of the Earth. 

eml_asteroids  Play a game of Asteroids  
eml_fire  Simulations of burning fire  
sf_tetris2  'j', 'l'  move left and right
'i', 'k'  rotate left and right SPACE  drop 'p'  pause 'q'  quit 

ballode  Simulate a demo of a bouncing ball.  
batonode  Simulate the motion of a thrown baton.  
sf_semantics_hotel_checkin  Simulate Hotel Checkins  
sf_traffic_light  Simulating traffic lights at intersections  
sf_fitness  Simulate the smartwatch  
klein1  This example shows how to generate a Klein bottle.
A Klein bottle is a nonorientable surface in fourdimensional space. It is formed by attaching two Mobius strips along their common boundary. 

xpklein  This example shows how to display a selfintersecting Klein bottle.
A Klein bottle is a nonorientable surface in fourdimensional space. It is formed by attaching two Mobius strips along their common boundary. 

brussode  Surface plots of brusselator  
why  Randomly generated answers to life , universe and everything  
iburgersode / burgersode  Burgers' equation solved as implicit ODE system  
sf_stickslip  Stick  slip friction simulations  
sfediticon  Simulink icons that enable to create basic 16 * 16 icon editor  
amp1dae  Stiff differentialalgebraic equation (DAE) from electrical circuits  
taylortool  A Taylor Series Approximation calculator  
sf_climate_control  Simulate an environmental climate control (Temp and humidity) for a chamber  
tori4  This example shows how to generate four linked unknotted tori by rotating four offcenter circles.  
ardemo  Interactive axes properties demonstration  
rlc_gui  Interactive GUI showing the relationship between the physical parameters of common RLC circuits and the time and frequency responses of those circuits.
* Lowpass RLC network * Highpass RLC network * Bandpass RLC network * Bandstop RLC network 

sf_security  Demonstrations of security system of door, window and mention sensor in a home  
sf_server  Display random numbers to serve the assigned clients  
step  Shows a randomly generated stable Transfer Function Model  
imagesc  Shows the images of a boy.
To correct it , into correct orientation , type imagesc
colormap(gray(32));
axis ij image off;


wernerboy  This example shows how to create Boy's surface  
transpdemo  This example shows how to modify the transparency value for graphics objects to reveal structure that is obscured with opaque objects.  
sf_car  Simulate car braking and throttle  
sf_yoyo  Simulate yoyo up and down and the energy  
sf_boiler  Simulation of temperature controller of boiler  
eml_aero_radar  Radar demo to estimate aircraft position using Kalman Filters 
Untested Easter Eggs
editsf_gui
sf_mandelbrot_fixpt
eomfun  Old
eigshow  Old
imagesAndVideo  Shows an moving images of rocket flying to the space
imagesc(hot) / imagesc(cool) / imagesc(hsv)  ???
old_sf_car
eml_clock
uitabledemo  ???
 ???
sf_tictacflow  SIMULINK project to simulate a game of Tic Tac Toe against AI

wrldtrv  Show great circle flight routes around the globe
xpquad  ???
xpsound  ???
Not working
sfbus_demo
sf_moore_traffic_light
sf_bidder
sf_power_window
NOTE: If there are any readers who knows what is the ??? easter eggs represent, you may kindly add in.
References
edit^{[1]} ^{[2]} ^{[3]} ^{[4]} ^{[5]}
 ↑ https://blogs.mathworks.com/steve/2006/10/17/thestorybehindthematlabdefaultimage/
 ↑ https://web.archive.org/web/20210615225906/https://undocumentedmatlab.com/articles/imageeasteregg
 ↑ https://web.archive.org/web/20210803075033/https://undocumentedmatlab.com/articles/spyeastereggtake2
 ↑ https://web.archive.org/web/20210123224206/https://ashanpeiris.blogspot.com/2014/12/matlabeastereggs.html
 ↑ https://www.testingdocs.com/inbuiltgraphicaldemosinmatlab/