Re^4: Data visualisation.

> triangle inequality check

Already a visual test reveals that projecting the data into 2D wouldn't make sense:

      M
     / \
 27 /   \ 47
   /     \
  D ----- G
     77
[download]

27 + 47 = 74 < 77

     A    B    C    D    E    F    G   

G:  80  572  196  *77  351   63    0 ...
...
M:  70  567  191  *27  346   83  *47 ...
[download]

Cheers Rolf

( addicted to the Perl Programming Language)

updates

added table
improved wording

Comment on Re^4: Data visualisation. Select or Download Code

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Re^5: Data visualisation. by roboticus (Chancellor) on Jan 04, 2014 at 21:44 UTC
LanX: Yeah, my original triangle check was faulty. I only checked one case, rather than all three. Using your data, I had only a 1/3 chance of detecting that particular triangle as failing the inequality: 47 < 27 + 77 : Passes 27 < 47 + 77 : Passes 77 !< 27 + 47 : Fails... Since I only checked one case, I'd've missed a bad triangle. But my code didn't check all that many triangles, either, so it missed anyway. So I added an exhaustive check just for the helluvit. I've updated the node above accordingly. ...roboticus When your only tool is a hammer, all problems look like your thumb.	[reply]
Re^6: Data visualisation. by BrowserUk (Patriarch) on Jan 05, 2014 at 03:26 UTC
So I added an exhaustive check just for the helluvit. What does your code now do with the "bad triangles"? With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday' Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error. "Science is about questioning the status quo. Questioning authority". In the absence of evidence, opinion is indistinguishable from prejudice.	[reply]
Re^7: Data visualisation. by roboticus (Chancellor) on Jan 05, 2014 at 06:42 UTC
BrowserUk: Nothing, really. It just mentions them. If the dataset were a set of straight-line distances, then it could warn you that the data has an error in it. My code doesn't really care, though. If the triangle is "bad", I'll still calculate the intersection point where the lines would meet, were they long enough. ...roboticus When your only tool is a hammer, all problems look like your thumb.	[reply]
Re^8: Data visualisation. by BrowserUk (Patriarch) on Jan 05, 2014 at 09:54 UTC
Re^9: Data visualisation. by roboticus (Chancellor) on Jan 05, 2014 at 18:13 UTC
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Re^9: Data visualisation. by Anonymous Monk on Jan 05, 2014 at 10:17 UTC
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