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Show function for graphs is not working!

asked 2011-12-16 06:14:46 +0200

Naji gravatar image

updated 2011-12-16 06:23:34 +0200

Hi everyone,

Yesterday I wrote a code to generate a random semi-regular graph. The algorithm works in this way: 1)It chooses vertices in numerical order 2)in each step it looks to see if the degree of the vertex is larger or smaller than the specified value for that vertex(which is a for first N/2 and b for second N/2 vertices) 3)it randomly adds an edge or remove one until the degree of vertex become acceptable 4)switches to the next vertex. However when I use show() function to see what is happening in each step, the result is frustrating, the Show() function shows a graph like what it should but the degrees are not associated with the correct vertices! for example most of the time even in the first cycle of the while loop, it should assign 3 edges to the '0' vertex. When I print the neighbours of '0' with "print G[0]" I get '[1,3,4]' but then in the plotted graph neighbours of '0' are '1' and '2' and '5'. I don't understand what is wrong with this Sage?! I am really exhausted of trying! My code is at:

Thanks a lot for the helps...

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answered 2011-12-16 12:54:17 +0200

Jason Grout gravatar image

updated 2012-01-02 12:56:29 +0200

Please see this discussion on sage-devel for discussion about this bug in the notebook and a resolution to the problem.

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answered 2011-12-16 06:55:04 +0200

Naji gravatar image

Solved! My code has a bug! However I want to mention it is really annoying that the bug of my code results in a bug of show function for SAGE!!

Thanks anyway!

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Can you elaborate on what the bug in your code was, and exactly how that was exposing a bug in the show function? We definitely want to fix any bugs in show.

Jason Grout gravatar imageJason Grout ( 2011-12-16 09:43:14 +0200 )edit

Try refreshing the page in your browser; it looks to me like a caching problem. I can reproduce this and am pushing it up to sage-devel.

DSM gravatar imageDSM ( 2011-12-16 10:42:01 +0200 )edit

answered 2011-12-31 20:34:27 +0200

Naji gravatar image

@Jason Grout: Sorry for the late reply I didn't notified. I just see it accidentally here!

I find out if your code is buggy(not related to show necessarily) it could result in malfunctioning of Show! or other calls in your program. In this case my code had a bug, but totally unrelated to the Show function but the problem rises in show function( and I don't remember what it was)

@DSM: Yes you are correct many times the problem is related to caching but this one not resolved with refreshing even!!

Thanks guys!

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Asked: 2011-12-16 06:14:46 +0200

Seen: 1,386 times

Last updated: Jan 02 '12