A Sample KnotTheory` Session: Difference between revisions
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out= <nowiki>{NegativeAmphicheiral, 1, 3, 3, 4, 1}</nowiki>}} |
out= <nowiki>{NegativeAmphicheiral, 1, 3, 3, 4, 1}</nowiki>}} |
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<!--END--> |
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===Polynomial Invariants=== |
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====[[The Alexander-Conway Polynomial]]==== |
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<!--$$alex = Alexander[K][t]$$--> |
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<!--END--> |
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<!--$$Conway[K][t]$$--> |
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<!--END--> |
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====="Similar" Knots (within the Atlas)===== |
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<!--$$Select[AllKnots[], (alex === Alexander[#][t])&]$$--> |
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Revision as of 14:26, 18 September 2005
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 |
K11a231 |
L8n6 |
T(7,5) |
Let us now introduce the four star knots that will accompany us throughout this session:
In[2]:=
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K = Knot[8, 17];
K11 = Knot[11, Alternating, 231];
L = Link[8, NonAlternating, 6];
TK = TorusKnot[7,5];
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Presentations
In[3]:=
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PD[K]
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Out[3]=
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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]]
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In[4]:=
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{GaussCode[K], GaussCode[L]}
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Out[4]=
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{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}]}
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In[5]:=
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DTCode[K]
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Out[5]=
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DTCode[6, 8, 12, 14, 4, 16, 2, 10]
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In[6]:=
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br = BR[K]
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Out[6]=
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BR[3, {-1, -1, 2, -1, 2, -1, 2, 2}]
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In[7]:=
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Show[BraidPlot[br]]
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Out[7]=
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-Graphics-
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In[8]:=
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{First[br], Crossings[br], BraidIndex[K]}
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Out[8]=
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{3, 8, 3}
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In[9]:=
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Show[DrawMorseLink[K]]
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Out[9]=
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-Graphics-
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In[10]:=
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Show[DrawMorseLink[L]]
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Out[10]=
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-Graphics-
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Three Dimensional Invariants
In[11]:=
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(#[K]&) /@ {
SymmetryType, UnknottingNumber, ThreeGenus,
BridgeIndex, SuperBridgeIndex, NakanishiIndex
}
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Out[11]=
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{NegativeAmphicheiral, 1, 3, 3, 4, 1}
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