Finite Type (Vassiliev) Invariants: Difference between revisions

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Vassiliev[2][K] computes the (standardly normalized) type 2 Vassiliev invariant of the knot K, i.e., the coefficient of z^2 in Conway[K][z]. Vassiliev[3][K] computes the (standardly normalized) type 3 Vassiliev invariant of the knot K, i.e., 3J''(1)-(1/36)J'''(1) where J is the Jones polynomial of K.
in = <nowiki>Vassiliev</nowiki> |
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out= <nowiki>Vassiliev[2][K] computes the (standardly normalized) type 2 Vassiliev invariant of the knot K, i.e., the coefficient of z^2 in Conway[K][z]. Vassiliev[3][K] computes the (standardly normalized) type 3 Vassiliev invariant of the knot K, i.e., 3J''(1)-(1/36)J'''(1) where J is the Jones polynomial of K.</nowiki>}}
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<pre style="color: red; border: 0px; padding: 0em"><nowiki>ListPlot[
in = <nowiki>ListPlot[
Join @@ Table[
Join @@ Table[
K = Knot[10, k] ; v2 = Vassiliev[2][K]; v3 = Vassiliev[3][K];
K = Knot[10, k] ; v2 = Vassiliev[2][K]; v3 = Vassiliev[3][K];
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],
],
PlotStyle -> PointSize[0.02], PlotRange -> All, AspectRatio -> 1
PlotStyle -> PointSize[0.02], PlotRange -> All, AspectRatio -> 1
]</nowiki></pre>
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{{Graphics2|n=2|imagename=Finite_Type_Vassiliev_Invariants_Out_2.gif}}
img= Finite_Type_Vassiliev_Invariants_Out_2.gif |
out= <nowiki>-Graphics-</nowiki>}}
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Revision as of 14:19, 30 August 2005


(For In[1] see Setup)

In[1]:= ?Vassiliev
Vassiliev[2][K] computes the (standardly normalized) type 2 Vassiliev invariant of the knot K, i.e., the coefficient of z^2 in Conway[K][z]. Vassiliev[3][K] computes the (standardly normalized) type 3 Vassiliev invariant of the knot K, i.e., 3J''(1)-(1/36)J'''(1) where J is the Jones polynomial of K.

Thus, for example, let us reproduce Willerton's "fish" (arXiv:math.GT/0104061), the result of plotting the values of against the values of , where is the (standardly normalized) type 2 invariant of , is the (standardly normalized) type 3 invariant of , and where runs over a set of knots with equal crossing numbers (10, in the example below):

In[3]:= ListPlot[ Join @@ Table[ K = Knot[10, k] ; v2 = Vassiliev[2][K]; v3 = Vassiliev[3][K]; {{v2, v3}, {v2, -v3}}, {k, 165} ], PlotStyle -> PointSize[0.02], PlotRange -> All, AspectRatio -> 1 ]
Finite Type Vassiliev Invariants Out 2.gif
Out[3]= -Graphics-