What matlab easter eggs do you know?
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Please post the easter eggs that you have found so far if they aren't already posted by someone else.
Let's try to make a good Matlab easter egg list because it seems that there isn't one.
What should be posted:
- Unexpected but intentional behaviour
- Special things that the programmers left for us to discover
- Extra code inside a function that can be used for other purposes
- Hidden pictures and audio clips
What shouldn't be posted:
- Repeated Easter Eggs, if someone already posted it please don't repeat
- Bugs in functions that cause trouble and might be fixed in later versions
- Matlab games that come with the program unless they aren't mentioned in the documentation (the games are in the other demos, try the xpbombs and fifteen, you can even see the code for both games)
14 Comments
Answers (9)
Kenneth Eaton
on 25 Feb 2011
Edited: Kenneth Eaton
on 11 Dec 2017
As Steve discussed in one of his blog posts, the default image in MATLAB is actually a steganographic image:
image

 
Just looks like an upside-down little boy, right? Well, if you rotate the 53-bits of the double precision fraction component so that each becomes the highest valued bit, you can easily see the hidden images:
 

 
Here's how I made the above image:
defImage = pow2(get(0,'DefaultImageCData'),47);
imgCell = repmat({zeros(size(defImage))},8,7);
for shift = 0:52
imgCell{shift+1} = bitrotate(defImage,shift);
end;
allImages = cell2mat(imgCell.');
imshow(allImages,[min(allImages(:)) max(allImages(:))]);
NOTE: bitrotate is a version of the built-in bitshift that I wrote to perform a circular shift of the bit pattern instead of discarding bits that overflow. I'll be placing bitrotate on the FEX soon, but for now you can just replace it with bitshift in the above code.
2 Comments
Paulo Silva
on 25 Feb 2011
6 Comments
Image Analyst
on 26 Jan 2012
Paulo, your avatar is no longer the "spy" image that pops up - it's Sean's dog (I think). Sean's lalala function is not in R2011b - maybe it will come out in R2012a.
Andrew Newell
on 25 Feb 2011
5 Comments
Sean de Wolski
on 25 Feb 2011
Paulo, search Steve Eddin's Blog for 'image function' (or similar). There is quite a lot to learn there!
Saurav Kumar
on 25 Apr 2011
surf(membrane) gives mathworks logo
imagesc(cool) gives the cool colors
imagesc(hot)
Image Analyst
on 26 Jan 2012
Not sure if they qualify as Easter eggs, but type these on the command line (verified on R2011b):
- why
- why are there too many input arguments?
- xpbombs
- fifteen
- spy (new image is probably only version R2011b or later - clearly Sean has had some influence since he joined the Mathworks staff)
- x=[-2:.001:2],y=(sqrt(cos(x)).*cos(200*x)+sqrt(abs(x))-0.7).*(4-x.*x).^0.01,plot(x,y);
On http://www.walkingrandomly.com/?p=2949, Cleve says " As our code base has increased, including such goodies in the MATLAB core has become problematic because of the strain it puts on rigorous automated testing. It is still possible to include them in a few “leaf” M functions, like “spy”, that other functions do not depend upon." so they will probably be fewer as time goes on.
0 Comments
Dennis Jaheruddin
on 27 Nov 2013
Not sure if it is really an easter egg, it is a bit simpler than most others.
The description of this function surprised me:
- eomfun
Note that it is only found in the help, not in the doc.
1 Comment
Image Analyst
on 27 Nov 2013
Easter eggs come and go. It's not in release R2013a. What version did you verify it in?
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