A Sample KnotTheory` Session

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Revision as of 14:20, 18 September 2005 by Drorbn (talk | contribs) (→‎Setup)
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Setup

The first step is to load KnotTheory` as in the Setup section:

In[1]:= << KnotTheory`

Loading KnotTheory` (version of September 14, 2005, 13:37:36)...

8 17.gif
8_17
K11a231.gif
K11a231
L8n6.gif
L8n6
T(7,5).jpg
T(7,5)

Let us now introduce the four star knots that will accompany us throughout this session:

In[2]:= K = Knot[8, 17]; K11 = Knot[11, Alternating, 231]; L = Link[8, NonAlternating, 6]; TK = TorusKnot[7,5];

Presentations

In[3]:= PD[K]
Out[3]= PD[X[6, 2, 7, 1], X[14, 8, 15, 7], X[8, 3, 9, 4], X[2, 13, 3, 14], X[12, 5, 13, 6], X[4, 9, 5, 10], X[16, 12, 1, 11], X[10, 16, 11, 15]]
In[4]:= {GaussCode[K], GaussCode[L]}
Out[4]= {GaussCode[1, -4, 3, -6, 5, -1, 2, -3, 6, -8, 7, -5, 4, -2, 8, -7], GaussCode[{1, -7, 2, -8}, {-5, 4, -6, 3}, {7, -1, -4, 5, 8, -2, -3, 6}]}
In[5]:= DTCode[K]
Out[5]= DTCode[6, 8, 12, 14, 4, 16, 2, 10]
In[6]:= br = BR[K]
Out[6]= BR[3, {-1, -1, 2, -1, 2, -1, 2, 2}]
In[7]:= Show[BraidPlot[br]]
A Sample KnotTheory Session Out 7.gif
Out[7]= -Graphics-
In[8]:= {First[br], Crossings[br], BraidIndex[K]}
Out[8]= {3, 8, 3}
In[9]:= Show[DrawMorseLink[K]]
A Sample KnotTheory Session Out 9.gif
Out[9]= -Graphics-
In[10]:= Show[DrawMorseLink[L]]
A Sample KnotTheory Session Out 10.gif
Out[10]= -Graphics-

Three Dimensional Invariants

In[11]:= (#[K]&) /@ { SymmetryType, UnknottingNumber, ThreeGenus, BridgeIndex, SuperBridgeIndex, NakanishiIndex }
Out[11]= {NegativeAmphicheiral, 1, 3, 3, 4, 1}