lcz

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1 years, 282 days

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These are replies submitted by lcz

@vv  Fortunately, I found an alternative.  Some people did a lot of work

http://crossings.uos.de/ 

@vv Indeed. I might be asking more broadly. 

I once asked such a question about crossing number of graph :

https://www.mapleprimes.com/questions/228584--Someone-Can-Help-Me--To-Compute-Crossing

This can be found in SageMath, but it is very slow. Of course, it was expected.

My goal is to test whether a given graph is 1-planar. Of course, it is difficult! We tend to consider the combination method. But we can try draw different drawing  before we prove it. This may involve different isomorphism drawing of graph.

 

 

@acer  Thanks, This is good enough.

@Carl Love Thanks for the advice. Your suggestion is valid for dealing with parallel edges. But I still can't handle it effectively.

I used FindEulerianCycle in mathematica  indirectly by G-e7+{13}.

  g = Graph[{1 <-> 2, 1 <-> 3, 1 <-> 4, 3 <-> 4, 3 <-> 4, 2 <-> 4, 
   1 <-> 3}, VertexLabels -> Automatic]
 

FindEulerianCycle[g, All]

We found 16 Eulerian trails. That's all we want. I don't know how to do in Maple. 

 There is no  function like  FindEulerianCycle[g, All]

@vv Thanks ,Good ideas!

@nm  Thanks But Why use A^+? A may be enough.

 

 

 

@Kitonum  Extremely grateful! One more question I care about.

how do I estimate errors  in maple if I use Optimization:-Maximize  .   does maple have any tools to analyze?

@Carl Love  Thanks I learn another good trick from you.

@nm   extremely grateful

@nm  Thanks ! For simplicity,  furthermore I'd like to let (5435 + 3*sqrt(515793))^(1/3)=t, but fail.

subs((5435 + 3*sqrt(515793))^(1/3)=t,s1)

@tomleslie  This is good, but it seems to be less thorough than the above method of vv.

@vv  Thnaks!   expand is  more  stronger than simplify and value. It's weird.

@Carl Love 

I see, thank you!

@Pascal4QM Thanks it is useful!

@Carl Love 

When f (specific expression) is very complicated, in order to write concisely

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