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StatePolytope :: isStable

isStable -- determines whether the mth Hilbert point of I is GIT stable

Synopsis

Description

Bayer and Morrison showed that GIT stability of the mth Hilbert point of I with respect to the maximal torus acting on a polynomial ring by scaling the variables can be tested by whether Statem(I) contains a certain point.
i1 : R = QQ[a..d];
i2 : I = ideal(a*c-b^2,a*d-b*c,b*d-c^2);

o2 : Ideal of R
i3 : isStable(3,I)
This is the Gfan program for computing Groebner fans and tropical varieties.
Use the command "gfan list" to view all subcommands.
The command "gfan" is deprecate for computing all Groebner bases of an ideal.
Please use subcommand "gfan _bases" instead. Awaiting input. <Ctrl>-D to end.
LP algorithm being used: "cddgmp".
polymake: used package cdd
  cddlib
  Implementation of the double description method of Motzkin et al.
  Copyright by Komei Fukuda.
  http://www.ifor.math.ethz.ch/~fukuda/cdd_home/cdd.html

polymake: used package ppl
  The Parma Polyhedra Library (PPL): A C++ library for convex polyhedra
  and other numerical abstractions.
  http://www.cs.unipr.it/ppl/

VERTICES
1 9 6 6 9
1 6 12 3 9
1 4 14 5 7
1 3 14 8 5
1 9 3 12 6
1 7 5 14 4
1 5 8 14 3
1 3 12 12 3

This is the Gfan program for computing Groebner fans and tropical varieties.
Use the command "gfan list" to view all subcommands.
The command "gfan" is deprecate for computing all Groebner bases of an ideal.
Please use subcommand "gfan _bases" instead. Awaiting input. <Ctrl>-D to end.
LP algorithm being used: "cddgmp".
polymake: used package cdd
  cddlib
  Implementation of the double description method of Motzkin et al.
  Copyright by Komei Fukuda.
  http://www.ifor.math.ethz.ch/~fukuda/cdd_home/cdd.html

polymake: used package ppl
  The Parma Polyhedra Library (PPL): A C++ library for convex polyhedra
  and other numerical abstractions.
  http://www.cs.unipr.it/ppl/

VERTICES
1 9 6 6 9
1 6 12 3 9
1 4 14 5 7
1 3 14 8 5
1 9 3 12 6
1 7 5 14 4
1 5 8 14 3
1 3 12 12 3


o3 = true
i4 : I = ideal(a^2,b^2,b*c);

o4 : Ideal of R
i5 : isStable(3,I) 
This is the Gfan program for computing Groebner fans and tropical varieties.
Use the command "gfan list" to view all subcommands.
The command "gfan" is deprecate for computing all Groebner bases of an ideal.
Please use subcommand "gfan _bases" instead. Awaiting input. <Ctrl>-D to end.
LP algorithm being used: "cddgmp".
polymake: used package cdd
  cddlib
  Implementation of the double description method of Motzkin et al.
  Copyright by Komei Fukuda.
  http://www.ifor.math.ethz.ch/~fukuda/cdd_home/cdd.html

polymake: used package ppl
  The Parma Polyhedra Library (PPL): A C++ library for convex polyhedra
  and other numerical abstractions.
  http://www.cs.unipr.it/ppl/

VERTICES
1 11 13 6 3

This is the Gfan program for computing Groebner fans and tropical varieties.
Use the command "gfan list" to view all subcommands.
The command "gfan" is deprecate for computing all Groebner bases of an ideal.
Please use subcommand "gfan _bases" instead. Awaiting input. <Ctrl>-D to end.
LP algorithm being used: "cddgmp".
polymake: used package cdd
  cddlib
  Implementation of the double description method of Motzkin et al.
  Copyright by Komei Fukuda.
  http://www.ifor.math.ethz.ch/~fukuda/cdd_home/cdd.html

polymake: used package ppl
  The Parma Polyhedra Library (PPL): A C++ library for convex polyhedra
  and other numerical abstractions.
  http://www.cs.unipr.it/ppl/

VERTICES
1 33/4 33/4 33/4 33/4
1 11 13 6 3


o5 = false

Ways to use isStable :