Undocumented Matlab
  • SERVICES
    • Consulting
    • Development
    • Training
    • Gallery
    • Testimonials
  • PRODUCTS
    • IQML: IQFeed-Matlab connector
    • IB-Matlab: InteractiveBrokers-Matlab connector
    • EODML: EODHistoricalData-Matlab connector
    • Webinars
  • BOOKS
    • Secrets of MATLAB-Java Programming
    • Accelerating MATLAB Performance
    • MATLAB Succinctly
  • ARTICLES
  • ABOUT
    • Policies
  • CONTACT
  • SERVICES
    • Consulting
    • Development
    • Training
    • Gallery
    • Testimonials
  • PRODUCTS
    • IQML: IQFeed-Matlab connector
    • IB-Matlab: InteractiveBrokers-Matlab connector
    • EODML: EODHistoricalData-Matlab connector
    • Webinars
  • BOOKS
    • Secrets of MATLAB-Java Programming
    • Accelerating MATLAB Performance
    • MATLAB Succinctly
  • ARTICLES
  • ABOUT
    • Policies
  • CONTACT

Spy Easter egg

April 11, 2009 4 Comments

For the 2009 Easter holiday, I thought I’d post a Matlab Easter egg, which I found on http://www.eeggs.com/items/47352.html: spy is a built-in stock Matlab function for visualizing sparse matrices. If you run spy with no input arguments, it uses an undocumented default built-in sparse matrix that generates one of the spies in the famous Spy vs. Spy comics series:

spy;

spy;

Matlab spy Easter egg

Related posts:

  1. Spy Easter egg take 2 – The default spy Easter-egg image in the spy function has recently changed. ...
  2. Image Easter egg – The default image presented by Matlab's image function has a very interesting undocumented story....
  3. Undocumented scatter plot behavior – The scatter plot function has an undocumented behavior when plotting more than 100 points: it returns a single unified patch object handle, rather than a patch handle for each specific point as it returns with 100 or less points....
  4. Performance: scatter vs. line – In many circumstances, the line function can generate visually-identical plots as the scatter function, much faster...
  5. Using Infiniband with Matlab Parallel Computing Toolbox – Infiniband networking can significantly improve PCT performance in Matlab parallelization and distributed computing. ...
  6. Bar plot customizations – Matlab bar charts can be customized in various nifty ways. ...
Easter egg Pure Matlab spy Undocumented feature
Print Print
« Previous
Next »
4 Responses
  1. Naor April 12, 2009 at 15:46 Reply

    ‘spy’ with no arguments was one of the first MATLAB commands I learned 🙂
    another one was ‘why’ with no arguments, maybe you consider that an Easter egg as well…

    • Yair Altman April 12, 2009 at 23:08 Reply

      @Naor – the difference is that why with no args is documented, so it’s fun but not a real Easter egg.
      Spy with no args is not documented.

  2. Image Easter egg | Undocumented Matlab April 6, 2010 at 10:28 Reply

    […] Last year I presented the Matlab Spy Easter egg for the 2009 Easter holiday. This year, slightly late, I present another Easter egg […]

  3. Spy Easter egg take 2 | Undocumented Matlab April 5, 2012 at 00:36 Reply

    […] Three years ago, I posted a short post about Matlab’s built-in Easter egg in the spy function […]

Leave a Reply
HTML tags such as <b> or <i> are accepted.
Wrap code fragments inside <pre lang="matlab"> tags, like this:
<pre lang="matlab">
a = magic(3);
disp(sum(a))
</pre>
I reserve the right to edit/delete comments (read the site policies).
Not all comments will be answered. You can always email me (altmany at gmail) for private consulting.

Click here to cancel reply.

Useful links
  •  Email Yair Altman
  •  Subscribe to new posts (email)
  •  Subscribe to new posts (feed)
  •  Subscribe to new posts (reader)
  •  Subscribe to comments (feed)
 
Accelerating MATLAB Performance book
Recent Posts

Speeding-up builtin Matlab functions – part 3

Improving graphics interactivity

Interesting Matlab puzzle – analysis

Interesting Matlab puzzle

Undocumented plot marker types

Matlab toolstrip – part 9 (popup figures)

Matlab toolstrip – part 8 (galleries)

Matlab toolstrip – part 7 (selection controls)

Matlab toolstrip – part 6 (complex controls)

Matlab toolstrip – part 5 (icons)

Matlab toolstrip – part 4 (control customization)

Reverting axes controls in figure toolbar

Matlab toolstrip – part 3 (basic customization)

Matlab toolstrip – part 2 (ToolGroup App)

Matlab toolstrip – part 1

Categories
  • Desktop (45)
  • Figure window (59)
  • Guest bloggers (65)
  • GUI (165)
  • Handle graphics (84)
  • Hidden property (42)
  • Icons (15)
  • Java (174)
  • Listeners (22)
  • Memory (16)
  • Mex (13)
  • Presumed future risk (394)
    • High risk of breaking in future versions (100)
    • Low risk of breaking in future versions (160)
    • Medium risk of breaking in future versions (136)
  • Public presentation (6)
  • Semi-documented feature (10)
  • Semi-documented function (35)
  • Stock Matlab function (140)
  • Toolbox (10)
  • UI controls (52)
  • Uncategorized (13)
  • Undocumented feature (217)
  • Undocumented function (37)
Tags
ActiveX (6) AppDesigner (9) Callbacks (31) Compiler (10) Desktop (38) Donn Shull (10) Editor (8) Figure (19) FindJObj (27) GUI (141) GUIDE (8) Handle graphics (78) HG2 (34) Hidden property (51) HTML (26) Icons (9) Internal component (39) Java (178) JavaFrame (20) JIDE (19) JMI (8) Listener (17) Malcolm Lidierth (8) MCOS (11) Memory (13) Menubar (9) Mex (14) Optical illusion (11) Performance (78) Profiler (9) Pure Matlab (187) schema (7) schema.class (8) schema.prop (18) Semi-documented feature (6) Semi-documented function (33) Toolbar (14) Toolstrip (13) uicontrol (37) uifigure (8) UIInspect (12) uitools (20) Undocumented feature (187) Undocumented function (37) Undocumented property (20)
Recent Comments
  • Marcel (9 days 20 hours ago): Hi, I am trying to set the legend to Static, but this command seems not to work in R2022a anymore: set(gca,’LegendColorbarL isteners’,[]); Any ideas? THANKS / marcel
  • Gres (10 days 0 hours ago): In 2018b, you can get the icons by calling [hh,icons,plots,txt] = legend({‘Line 1’});
  • Yair Altman (11 days 19 hours ago): @Mitchell – in most cases the user wants a single string identifier for the computer, that uniquely identifies it with a distinct fingerprint that is different from any...
  • Mitchell (12 days 3 hours ago): Great post! I’m not very familiar with the network interfaces being referenced here, but it seems like the java-based cross-platform method concatenates all network...
  • Yair Altman (14 days 21 hours ago): Dani – You can use jViewport.setViewPosition(java .awt.Point(0,0)) as I showed in earlier comments here
  • dani (15 days 17 hours ago): hi!! how i can set the horizontal scrollbar to the leftside when appearing! now it set to right side of text
  • Yair Altman (24 days 13 hours ago): Dom – call drawnow *just before* you set hLine.MarkerHandle.FaceColorTy pe to 'truecoloralpha'. Also, you made a typo in your code: it’s truecoloralpha, not...
  • Dom (25 days 12 hours ago): Yair I have tried your code with trucoloralpha and the markers do not appear transparent in R2021b, same as for Oliver.
  • Yair Altman (28 days 19 hours ago): Ren – This is usually the expected behavior, which avoids unnecessary duplications of the Excel process in CPU/memory. If you want to kill the process you can always run...
  • Yair Altman (29 days 9 hours ago): When you use plot() without hold(‘on’), each new plot() clears the axes and draws a new line, so your second plot() of p2 caused the first plot() line (p1) to be...
  • Cesim Dumlu (35 days 16 hours ago): Hello. I am trying to do a gradient plot for multiple functions to be displayed on the same axes and each one is colorcoded by respective colordata, using the same scaling. The...
  • Yair Altman (43 days 19 hours ago): @Veronica – you are using the new version of uitree, which uses HTML-based uifigures, and my post was about the Java-based uitree which uses legacy Matlab figures. For...
  • Veronica Taurino (43 days 19 hours ago): >> [txt1,txt2] ans = ‘abrakadabra’
  • Veronica Taurino (43 days 20 hours ago): Hello, I am just trying to change the uitree node name as you suggested: txt1 = 'abra'; txt2 = 'kadabra'; node.setName([txt1,txt2]); >> "Unrecognized method, property, or...
  • Yair Altman (46 days 20 hours ago): The version of JGraph that you downloaded uses a newer version of Java (11) than the one that Matlab supports (8). You need to either (1) find an earlier version of JGraph that...
Contact us
Undocumented Matlab © 2009 - Yair Altman
This website and Octahedron Ltd. are not affiliated with The MathWorks Inc.; MATLAB® is a registered trademark of The MathWorks Inc.
Scroll to top