# 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

Command Description Picture/Examples
cruller Construct a cruller by revolving the eccentric ellipse defined by the function XYCRULL.
date Returns date as in dd-mmm-yyyy format 08-Aug-2022
sldemo_fuelsys Simulations of Fault-Tolerant 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

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 L-shaped membrane logo with MATLAB(R) lighting.
membrane Plot a 3-D 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 two-dimensional truss.
vibes This demonstration solves the wave equation for the vibrations of an L-shaped membrane.
makevase Generate and plot a surface of revolution. The body-of-revolution 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 tube-like 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 four-dimensional space. It is formed by attaching two Mobius strips along their common boundary.

xpklein This example shows how to display a self-intersecting Klein bottle.

A Klein bottle is a nonorientable surface in four-dimensional 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 differential-algebraic 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 off-center 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.

* Low-pass RLC network

* High-pass RLC network

* Band-pass RLC network

* Band-stop 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

### Untested Easter Eggs

sf_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

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.