DMUG-Archiv 2018

Frühere   Chronologischer Index   Spätere
Vorherige   Thematischer Index   Nächste

Re: [Dmug] knot theory package

 Hi Udo,

   thanks, so I know now where to start working.

Best wishes
Stephan

Quoting Udo und Susanne Krause <su.krause@XXXXXXX.ch>:

Hi Stephan, 
   
just try it, https://knotplot.com/dowker/dowker.html has a knot with 36 crossings
   
  In[6]:= TimeConstrained[
            DrawPD[DTCode[40, 24, 10, 30, 22, 52, 32, 64, 46, 12, 6, 42, 60, 2,                 8, 50, 66, 16, 62, 58, 28, 4, 54, 34, 14, 20, 68, 36, 72, 26, 70, 
               56, 48, 18, 44, 38], {Gap -> 0.025}], 180]

KnotTheory::credits: The GaussCode to PD conversion was written by Siddarth Sankaran at the University of Toronto in the summer of 2005.
   
resulting in a planar diagram, a shot into to wild shows potential to check the input 
   
   
  In[8]:= TimeConstrained[
DrawPD[DTCode[2 RandomInteger[{1, 32}, {36}]], {Gap -> 0.025}], 180]

During evaluation of In[8]:= Part::partw: Part {1,9} of {True} does not exist. >>

During evaluation of In[8]:= Part::partw: Part {1,12} of {True} does not exist. >>

During evaluation of In[8]:= Part::partw: Part 1 of {} does not exist. >>

During evaluation of In[8]:= General::stop: Further output of Part::partw will be suppressed during this calculation. >>

During evaluation of In[8]:= Part::pkspec1: The expression {}[[1]] cannot be used as a part specification. >>

During evaluation of In[8]:= Part::pkspec1: The expression {}[[2]] cannot be used as a part specification. >>

During evaluation of In[8]:= Part::pkspec1: The expression {}[[1]] cannot be used as a part specification. >>

During evaluation of In[8]:= General::stop: Further output of Part::pkspec1 will be suppressed during this calculation. >>

During evaluation of In[8]:= Set::shape: Lists {{KnotTheory`GaussCode`c1$6630,KnotTheory`GaussCode`c2$6630,KnotTheory`GaussCode`s}} and {} are not the same shape. >>

During evaluation of In[8]:= Set::shape: Lists {{KnotTheory`GaussCode`c1$6630,KnotTheory`GaussCode`c2$6630,KnotTheory`GaussCode`s}} and {} are not the same shape. >>

During evaluation of In[8]:= Set::shape: Lists {{KnotTheory`GaussCode`c1$6630,KnotTheory`GaussCode`c2$6630,KnotTheory`GaussCode`s}} and {} are not the same shape. >>

During evaluation of In[8]:= General::stop: Further output of Set::shape will be suppressed during this calculation. >>

Out[8]= $Aborted
   
just this reference https://pyknotid.readthedocs.io/en/latest/sources/catalogue/index.html#downloading-the-database goes systematically with up to 15 crossings. There are of course pretzel knots and torus knots with potentially any number of crossings.
   
Before you can burn calculation time you need something to calculate which might be not so obviously to find. One rather exterior approach could be to classify - you could even try to use Mathematicas machine learning capabilities - the given systematic data collections to find out pattern for existing knots (or links) and use that to guess or construct similar knots, but with higher crossing number, by combining the patterns found in a meaningful way. Look around.
   
  Best regards
  Udo.
   
   
   
On Wed, 29 Aug 2018 11:27:12 +0200, Stephan Rosebrock <rosebrock@XXXXXXX.de> wrote:

Hi Udo,

   thanks for your answer. Your suggestion only works for knots and links for which there are already tables implemented, right? What, if I want to have a link with more crossings (about 22 or even more). There are no tables for them, right? Since this is part of a very long going project (years) I don't mind long calculation time.

Best wishes
Stephan

Quoting Udo und Susanne Krause <su.krause@XXXXXXX.ch>:

Hello Stephan, 
     
    you shouldn't, period. The manual help once again
     
    http://katlas.org/wiki/DT_(Dowker-Thistlethwaite)_Codes
     
    says 
     
DTCode also acts as a "type caster", so for example, DTCode[K] where K is is a named knot or link returns the DT code of K.
       <snip>

   *********************************************************
Dr. Stephan Rosebrock

Paedagogische Hochschule Karlsruhe
Bismarckstr. 10
76133 Karlsruhe
Deutschland / Germany

e-mail:    rosebrock@XXXXXXX.de
Homepage:  http://www.rosebrock.ph-karlsruhe.de/
Tel:  0721-925-4275
Fax:  0721-925-4249
*********************************************************

 
 *********************************************************
Dr. Stephan Rosebrock

Paedagogische Hochschule Karlsruhe
Bismarckstr. 10
76133 Karlsruhe
Deutschland / Germany

e-mail:    rosebrock@XXXXXXX.de
Homepage:  http://www.rosebrock.ph-karlsruhe.de/
Tel:  0721-925-4275
Fax:  0721-925-4249
*********************************************************
_______________________________________________
DMUG Deutschsprachiges Mathematica-Forum demug@XXXXXXX.ch
http://www.mathematica.ch/mailman/listinfo/demug
Archiv: http://www.mathematica.ch/archiv.html

Antworten:
Verweise:
Frühere   Chronologischer Index   Spätere
Vorherige   Thematischer Index   Nächste

DMUG DMUG-Archiv, http://www.mathematica.ch/archiv.html