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Don't define Dimension for groups #43

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af8acdf
Don't define Dimension for groups
fingolfin Oct 18, 2023
36f2823
Minimal hack to make some things work again
fingolfin Oct 18, 2023
9cebb0b
Doc hack
fingolfin Oct 18, 2023
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1 change: 0 additions & 1 deletion archive/group2.gd
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Original file line number Diff line number Diff line change
Expand Up @@ -72,7 +72,6 @@ DeclareOperation( "ProjElWithFrobWithPSIsom",
[IsMatrix and IsFFECollColl, IsMapping, IsField,
IsGeneralMapping and IsSPGeneralMapping and IsOne] );
DeclareOperation( "ProjElsWithFrobWithPSIsom", [IsList, IsField] );
DeclareAttribute( "Dimension", IsProjGroupWithFrobWithPSIsom );
DeclareProperty( "CanComputeActionOnPoints", IsProjGroupWithFrobWithPSIsom );
DeclareOperation( "CorrelationOfProjectiveSpace", [ IsList, IsField] );
DeclareOperation( "CorrelationOfProjectiveSpace", [ IsList, IsMapping, IsField] );
Expand Down
24 changes: 0 additions & 24 deletions archive/group2.gi
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Expand Up @@ -1001,30 +1001,6 @@ InstallGlobalFunction( OnProjSubspacesExtended,
return VectorSpaceToElement(ps,newvec);
end );

# CHECKED 19/09/11 jdb
#############################################################################
#O Dimension( <g> )
# returns the dimension of the correlation group <g>. The dimension of this
# group is defined as the vector space dimension of the projective space
# of which <g> was defined as a projective group, or, in other words, as the
# size of the matrices.
##
InstallMethod( Dimension,
"for a projective group with Frobenius with vspace isomorphism",
[IsProjGroupWithFrobWithPSIsom],
function( g )
local gens;
if HasParent(g) then
return Dimension(Parent(g));
fi;
# Now start to investigate:
gens := GeneratorsOfGroup(g);
if Length(gens) > 0 then
return Length(gens[1]!.mat);
fi;
Error("dimension could not be determined");
end );

# CHECKED 20/09/11 jdb
#############################################################################
#P ActionOnAllPointsHyperplanes( <g> )
Expand Down
5 changes: 0 additions & 5 deletions doc/include/attributes_inventory.txt
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Expand Up @@ -30,10 +30,6 @@ A: ProjectiveDimension: IsElementOfLieGeometry
A: ProjectiveDimension: IsEmptySubspace
A: Dimension: IsLieGeometry

group.gd: attributes

A: Dimension: IsProjectiveGroupWithFrob

projectivespace.gd: attributes

A: ProjectivityGroup: IsProjectiveSpace
Expand All @@ -48,7 +44,6 @@ A: StandardFrame: IsSubspaceOfProjectiveSpace

correlations.gd: attributes

A: Dimension: IsProjGroupWithFrobWithPSIsom
A: GramMatrix: IsPolarityOfProjectiveSpace
A: CompanionAutomorphism: IsPolarityOfProjectiveSpace
A: SesquilinearForm: IsPolarityOfProjectiveSpace
Expand Down
2 changes: 0 additions & 2 deletions doc/include/methods_inventory.txt
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Expand Up @@ -219,7 +219,6 @@ M: ViewObj, [IsProjectiveGroupWithFrob and HasGeneratorsOfGroup],
M: ViewObj, [IsProjectiveGroupWithFrob and HasSize],
M: ViewObj, [IsProjectiveGroupWithFrob and HasGeneratorsOfGroup and HasSize],
M: BaseField, [IsProjectiveGroupWithFrob],
M: Dimension, [IsProjectiveGroupWithFrob],
M: OneImmutable, # was [IsGroup and IsProjectiveGroupWithFrob], I think might be
M: CanComputeActionOnPoints, [IsProjectiveGroupWithFrob],
M: ActionOnAllProjPoints, [ IsProjectiveGroupWithFrob ],
Expand Down Expand Up @@ -413,7 +412,6 @@ M: MatrixOfCorrelation, InstallMethod(MatrixOfCorrelation,[IsProjGrpElWithFrobWi
M: FieldAutomorphism, InstallMethod(FieldAutomorphism,[IsProjGrpElWithFrobWithPSIsomand IsProjGrpElWithFrobWithPSIsomRep],
M: ProjectiveSpaceIsomorphism, InstallMethod(ProjectiveSpaceIsomorphism,[IsProjGrpElWithFrobWithPSIsomand IsProjGrpElWithFrobWithPSIsomRep],
M: Embedding, [IsProjectiveGroupWithFrob, IsProjGroupWithFrobWithPSIsom],
M: Dimension, [IsProjGroupWithFrobWithPSIsom],
M: ActionOnAllPointsHyperplanes, [ IsProjGroupWithFrobWithPSIsom ],
M: CanComputeActionOnPoints, [IsProjGroupWithFrobWithPSIsom],
M: NiceMonomorphism, [IsProjGroupWithFrobWithPSIsom and CanComputeActionOnPoints and IsHandledByNiceMonomorphism], 50,
Expand Down
2 changes: 2 additions & 0 deletions doc/projgroups.xml
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Expand Up @@ -619,6 +619,7 @@ the base field of the vector space on which the group acts.
</Description>
</ManSection>

<!--
<ManSection>
<Attr Name="Dimension" Arg="g"/>
<Returns>a number</Returns>
Expand All @@ -627,6 +628,7 @@ the dimension of the vector space on which the group acts.
</Description>
</ManSection>
</Section>
-->


<Section>
Expand Down
1 change: 0 additions & 1 deletion lib/correlations.gd
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Expand Up @@ -74,7 +74,6 @@ DeclareOperation( "ProjElWithFrobWithPSIsom",
[IsMatrix and IsFFECollColl, IsMapping, IsField,
IsGeneralMapping and IsSPGeneralMapping and IsOne] );
DeclareOperation( "ProjElsWithFrobWithPSIsom", [IsList, IsField] );
DeclareAttribute( "Dimension", IsProjGroupWithFrobWithPSIsom );
DeclareProperty( "CanComputeActionOnPoints", IsProjGroupWithFrobWithPSIsom );

DeclareOperation( "CorrelationOfProjectiveSpace", [ IsList, IsField] );
Expand Down
26 changes: 1 addition & 25 deletions lib/correlations.gi
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Expand Up @@ -1340,30 +1340,6 @@ InstallGlobalFunction( OnProjSubspacesExtended,
return VectorSpaceToElement(ps,newvec);
end );

# CHECKED 19/09/11 jdb
#############################################################################
#O Dimension( <g> )
# returns the dimension of the correlation group <g>. The dimension of this
# group is defined as the vector space dimension of the projective space
# of which <g> was defined as a projective group, or, in other words, as the
# size of the matrices.
##
InstallMethod( Dimension,
"for a projective group with Frobenius with vspace isomorphism",
[IsProjGroupWithFrobWithPSIsom],
function( g )
local gens;
if HasParent(g) then
return Dimension(Parent(g));
fi;
# Now start to investigate:
gens := GeneratorsOfGroup(g);
if Length(gens) > 0 then
return NrRows(gens[1]!.mat);
fi;
Error("dimension could not be determined");
end );

# CHECKED 20/09/11 jdb
#############################################################################
#P ActionOnAllPointsHyperplanes( <g> )
Expand Down Expand Up @@ -1414,7 +1390,7 @@ InstallMethod( CanComputeActionOnPoints,
[IsProjGroupWithFrobWithPSIsom],
function( g )
local d,q;
d := Dimension( g );
d := NrRows(GeneratorsOfGroup(g)[1]!.mat);;
q := Size( BaseField( g ) );
if (q^d - 1)/(q-1) > FINING.LimitForCanComputeActionOnPoints then
return false;
Expand Down
2 changes: 0 additions & 2 deletions lib/group.gd
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Expand Up @@ -132,7 +132,6 @@ DeclareGlobalFunction( "OnProjSubspacesNoFrob" );
# as a projective semilinear group (i.e. a collineation group), and for these
# groups we have the operations defined (ml 05/11/2012)
#DeclareOperation( "ActionOnAllProjPoints", [IsProjectivityGroup] );
#DeclareAttribute( "Dimension", IsProjectivityGroup );
#DeclareProperty( "CanComputeActionOnPoints", IsProjectivityGroup );


Expand All @@ -158,7 +157,6 @@ DeclareGlobalFunction( "OnProjSubspacesWithFrob" );

DeclareOperation( "ActionOnAllProjPoints", [IsProjectiveGroupWithFrob] );

DeclareAttribute( "Dimension", IsProjectiveGroupWithFrob );
DeclareProperty( "CanComputeActionOnPoints", IsProjectiveGroupWithFrob );

DeclareGlobalFunction( "NiceMonomorphismByOrbit" );
Expand Down
59 changes: 3 additions & 56 deletions lib/group.gi
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Expand Up @@ -1765,59 +1765,6 @@ InstallMethod( BaseField,

# TO DO (22/03/2014): We ought to set the basefield on creating collineation groups.

# CHECKED 6/09/11 jdb
#############################################################################
#O Dimension( <g> )
# returns the dimension of the projective group <g>. The dimension of this
# group is defined as the vector space dimension of the projective space
# of which <g> was defined as a projective group, or, in other words, as the
# size of the matrices.
##

# ml 07/11/2012: I have taken out the view, print and display methods
# for projectivity groups, since these are also collineation groups in FinInG

#InstallMethod( Dimension,
# "for a projective group",
# [IsProjectivityGroup],
# function( g )
# local gens;
# if HasParent(g) then
# return Dimension(Parent(g));
# fi;
# # Now start to investigate:
# gens := GeneratorsOfGroup(g);
# if Length(gens) > 0 then
# return NrRows(gens[1]!.mat);
# fi;
# Error("dimension could not be determined");
# end );

# CHECKED 6/09/11 jdb
#############################################################################
#O Dimension( <g> )
# returns the dimension of the projective collineation group <g>. The dimension of this
# group is defined as the vector space dimension of the projective space
# of which <g> was defined as a projective group, or, in other words, as the
# size of the matrices.
##
InstallMethod( Dimension,
"for a projective collineation group",
[IsProjectiveGroupWithFrob],
function( g )
local gens;
if HasParent(g) and HasDimension(Parent(g)) then #JB: 22/03/2014: Made sure the parent had a dimension first
return Dimension(Parent(g));
fi;
# Now start to investigate:
gens := GeneratorsOfGroup(g);
if Length(gens) > 0 then
return NrRows(gens[1]!.mat);
elif IsTrivial(g) then #JB: 22/03/2014: The trivial group with no generators slipped through.
return NrRows(One(g)!.mat);
fi;
Error("dimension could not be determined");
end );

# CHECKED 6/09/11 jdb
#############################################################################
Expand Down Expand Up @@ -1911,7 +1858,7 @@ InstallMethod( CanComputeActionOnPoints,
[IsProjectiveGroupWithFrob],
function( g )
local d,q;
d := Dimension( g );
d := NrRows(GeneratorsOfGroup(g)[1]!.mat);;
q := Size( BaseField( g ) );
if (q^d - 1)/(q-1) > FINING.LimitForCanComputeActionOnPoints then
return false;
Expand Down Expand Up @@ -2061,7 +2008,7 @@ InstallMethod( ActionOnAllProjPoints,
local a,d,f,o,on,orb,v, m, j;
Info(InfoFinInG,4,"Using ActionOnAllProjPoints");
f := BaseField(pg);
d := Dimension(pg);
d := NrRows(GeneratorsOfGroup(pg)[1]!.mat);;
o := One(f);
on := One(pg);
v := ZeroMutable(on!.mat[1]);
Expand Down Expand Up @@ -2326,7 +2273,7 @@ InstallMethod( FindBasePointCandidates,
d := NrRows(gens[1]!.el!.mat);
else
f := BaseField(g);
d := Dimension(g);
d := NrRows(gens[1]!.mat);
fi;
cand := rec( points := NewMatrix(IsCMatRep, f,d, IdentityMat(d,f)), used := 0,
ops := ListWithIdenticalEntries(d,OnProjPointsWithFrob) );
Expand Down
1 change: 0 additions & 1 deletion old/group2old.gd
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Expand Up @@ -44,5 +44,4 @@ DeclareOperation( "ProjElWithFrobWithVSIsom",

DeclareOperation( "ProjElsWithFrobWithVSIsom", [IsList, IsField] );

DeclareAttribute( "Dimension", IsProjGroupWithFrobWithVSIsom );
DeclareProperty( "CanComputeActionOnPoints", IsProjGroupWithFrobWithVSIsom );
16 changes: 0 additions & 16 deletions old/group2old.gi
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Expand Up @@ -482,22 +482,6 @@ InstallGlobalFunction( OnPointsHyperplanesWithFrobWithVSIsom,
fi;
end );

InstallMethod( Dimension,
"for a projective group with Frobenius with vspace isomorphism",
[IsProjGroupWithFrobWithVSIsom],
function( g )
local gens;
if HasParent(g) then
return Dimension(Parent(g));
fi;
# Now start to investigate:
gens := GeneratorsOfGroup(g);
if Length(gens) > 0 then
return Length(gens[1]!.mat);
fi;
Error("dimension could not be determined");
end );

InstallMethod( ActionOnPointsHyperplanes,
"for a projective group with Frobenius with vspace isomorphism",
[ IsProjGroupWithFrobWithVSIsom ],
Expand Down