Spy Easter egg take 2
Posted By Yair Altman On April 4, 2012 | 6 Comments
Three years ago, I posted a short post [1] about Matlab’s built-in Easter egg in the spy function. Apparently, when running spy with no input arguments, it uses an undocumented default built-in sparse matrix that generates the white spy in the famous Spy vs. Spy [2] comics series:
>> spy;
As was recently reported [3] by Aurélien, the default built-in sparse matrix has changed in R2011a (not R2011b as in the original report):
If you ask me, the previous (white spy) image had more relevance to the spy function… I assume the new image was not chosen arbitrarily – if anyone has some insight as to why this image was chosen and its relevance to spy, please post a comment.
Addendum: The original spy image can still be generated using the following code snippet:
c = [';@3EA4:aei7]ced.CFHE;4\T>*Y>,dL0,HOQQMJLJE9PX[[Q.ZF.\JTCA1dd'
'<A;FB:;bfj8^df//DGIF<5]UF+ZH-eM>-IorRPNMPIE-Y\\R8[I8]SUDW2e+'
'=4BGC;<cgk9_e00DEOJG=6^VG,[I.fN?5jpsSQPNQPF.Z,]S9`S9cTWVX:+,'
':5CHD<=4hlh`f11EFPKHA7&WH-\J/gOC?kqtTRRORQJ8--^TB+T=dWYWY;,_'
';6D3E=>7imiag2IFOQLID8''XI.]K0"PD@l32UZhP//P988_WC,U>+Z^Y\<2`'
'<82BF>?8jnjbhLJGPRMJE9/YJ/`L1#QMC$;;V[iv09QE99,XD.YB,[_\]=3a'
'>9;CG?@9kokc2MKHQSOKF:0ZL0aM2$RNG%AAW\jw9E.FEE-_G8aG.d`]_W5+'
'?:CDH@A:lpld3NLIRTPLG=1[M1bN3%SOH4BBX]kx:J9LLL8`H9bJ/+d_dX6,'
'@;DEIAB;mqmePOMJSUQMJ>2\N2cO4&TPP@HCY^lyDKEMMN9+I@+S8,+deY7^'
'8@EFJBC<4rnfQPNPTVRNKB3]O3dP5''UQQCIDZ_mzEPFNNOE,RA,T9/,++\8_'
'9A2G3CD=544gRQPQUWUOLE4^P4"Q6(VRRIJE[`n{KQKOOPK-SE.W:F/,,]Z+'
':BDH4DE>655hSRQRVXVPMF5_Q5#R>)eSSJKF\ao0L.L-WUL.VF8XCH001_[,'
';3EI<EO?766iTSRSWYWQNG6$R6''S?*fTTlLQ]bp1M/P.XVP8[H9]DIDA=`\]'
'?4D3=FP@877jUTSTXZXROK7%S7(TF+gUUmMR^cq:N9Q8YZQ9_I>cIJEB>d_^'
'@5E@>GQA98b3VUTUY*YSPL8&T>)UI,hVhnNS_dr;PE.9Z[RCaR?+JTFC?e`+'
'79FA?HRB:9c4WVUVZ+ZWQM=,WG*VJ-"gi4OT`es<QL9E[\TD+SA,SWUVW+d,'
'8:3B@JSX;:dVXWVW[,[XRN>-XH+bK.#hj@PUvftDRMEF,]UH,UB.TYVWX,e\'
'9;ECAKTY<;eWYXWX\:)YSOE.YI,cL/$ikCqV1guE/PFL-^XI-YG/WZWXY1+]'
':AFDBLUZ=<fXZYXY,;*ZTPF/ZJ-dM0%j#Jrt2hxH0QKM8,YJ.ZI8[^YY\2,,'
';B3ECMV[>jgY[ZYZ-<7[XQG0[K.eN1&"$K2u:iyO9.PN9-_K8aJ9\_]\]82['
'?CEFDNW\?khZ\[Z[==8\YRH1\M/!O2''#%m31Bw0PE/QXE8+R9bS;da^]_93\'
'@2FGEOX]ali[]\[\>>9(ZSL2]N0"P3($&n;2Cx1QN9--L9,SA+T<+d__`:4,'
'A3GHFPY^bmj\^]\]??:)[TM3^O1%Q4)%''oA:D0:0OE.8ME-TE,XB,+`da;5['
'643IGQZ_cnk]_^]^@@;5\UN4_P2&R6*&(3B;E1<1PN99NL8WF.^C/,a+bY6,'
'7:F3HR[`dol^`_^_AA<6]VO5`Q3''S>+'');CBF:=:QOEEOO9_G8aH6/d,cZ[Y'
'8;G4IS\aep4_a`_-BD=7''XP6aR4(T?,(5@DCHCC;RPFLPPD`H9bJ70+0d\\Z'
'9BH>JT^bf45`ba`.CE@8(YQ7#S5)UD-)?AEDIDDD/QKMVQJ+S?cSDF,1e]a,'
':C3?K4_cg5[acbaADFA92ZR8$T6*VE.*@JFEJEEE0.NNWTK,U@+TEG0?+_bX'
';2D@L9`dh6\bdcbBEGD:3[S=)U7+cK/+CKGFLIKI9/OWZUL-VA,WIHB@,`cY'];
i = double(c(:)-32);
j = cumsum(diff([0; i])<=0) + 1;
S = sparse(i,j,1)';
spy(S)
Happy Easter / Passover everybody!
Categories: Low risk of breaking in future versions, Stock Matlab function, Undocumented feature
6 Comments (Open | Close)
Article printed from Undocumented Matlab: https://undocumentedmatlab.com
URL to article: https://undocumentedmatlab.com/articles/spy-easter-egg-take-2
URLs in this post:
[1] short post: http://undocumentedmatlab.com/blog/spy-easter-egg/
[2] Spy vs. Spy: http://en.wikipedia.org/wiki/Spy_vs._Spy
[3] reported: http://blog.developpez.com/matlab4geek/p10681/pensee-matlab-du-jour/notre-vieil-espion-qui-a-pris-sa-retrait/?page=2
[4] training courses: http://undocumentedmatlab.com/training/
[5] email me: mailto:%20altmany%20@gmail.com?subject=Matlab%20courses&body=Hi%20Yair,%20&cc=;&bcc=
[6] Spy Easter egg : https://undocumentedmatlab.com/articles/spy-easter-egg
[7] Image Easter egg : https://undocumentedmatlab.com/articles/image-easter-egg
[8] ishghandle's undocumented input parameter : https://undocumentedmatlab.com/articles/ishghandle-undocumented-input-parameter
[9] Plot LimInclude properties : https://undocumentedmatlab.com/articles/plot-liminclude-properties
[10] Plot legend title : https://undocumentedmatlab.com/articles/plot-legend-title
[11] Customizing axes part 5 – origin crossover and labels : https://undocumentedmatlab.com/articles/customizing-axes-part-5-origin-crossover-and-labels
[12] : http://www.mathworks.com/matlabcentral/answers/2001-what-matlab-easter-eggs-do-you-know#answer_3077
[13] : http://www.mathworks.com/matlabcentral/answers/contributors/3208495-sean-de-wolski
[14] : http://stackoverflow.com/questions/17378200/matlab-easter-egg-spy-vs-spy/17379616#17379616
Click here to print.
6 Comments To "Spy Easter egg take 2"
#1 Comment By Daniel Shub On April 4, 2012 @ 12:07
If you trust the comment at MATLAB answers: [12] it is Sean de Wolski’s dog. Sean is a relatively new employee at TMW and a frequent contributor to Answers. I think the dog is on his current avatar: [13]
#2 Comment By Michelle Hirsch On April 10, 2012 @ 09:00
Close, but it’s not Sean’s dog. The dog belongs to the lead developer of the sparse matrix functions in MATLAB.
#3 Comment By naor On April 4, 2012 @ 20:39
I too was disappointed last year when I realized the spy was gone. Perhaps it is still reachable in some undocumented way?
#4 Comment By Yair Altman On April 5, 2012 @ 00:39
@Naor – I’ve added an addendum showing how you can regenerate the old spy image
#5 Comment By Oleg Komarov On June 29, 2013 @ 04:18
Hi Yair,
the spy snippet has a vertcat error in c as a poster mentioned on SO. I answered with the error free snippet [14].
#6 Comment By Yair Altman On June 29, 2013 @ 11:03
@Oleg – thanks. This was due to a bug in the WordPress code that renders < characters – It's now fixed. I had to revert to a sub-optimal non-syntax-highlighted rendering of the code, but at least it's now correct.