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tensor: add_permuted_contractions works

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Jiri Pittner
2025-11-18 15:11:18 +01:00
parent 71c890c39b
commit 417a7d1d1a
2 changed files with 53 additions and 14 deletions
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46
t.cc
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@@ -4169,6 +4169,52 @@ cout<<"resulting index order = "<<y.names<<endl;
}
if(0)
{
int nn;
cin>>nn;
int r=4;
NRVec<INDEXGROUP> s(r);
for(int i=0; i<r; ++i)
{
s[i].number=1;
s[i].symmetry=0;
s[i].range=nn;
s[i].offset=0;
}
Tensor<double> x(s); x.randomize(1.);
INDEXNAME xlist[] = {"i","j","k","l"};
x.names=NRVec<INDEXNAME>(xlist);
Tensor<double> y(s); y.randomize(1.);
INDEXNAME ylist[] = {"m","n","j","i"};
y.names=NRVec<INDEXNAME>(ylist);
Tensor<double>z(s); z.clear();
INDEXNAME zlist[] = {"m","n","k","l"};
z.names=NRVec<INDEXNAME>(zlist);
Tensor<double>zz(z);
INDEX i1[]={{0,0},{1,0}};
INDEX i2[]={{3,0},{2,0}};
NRVec<INDEX> il1(i1);
NRVec<INDEX> il2(i2);
Tensor<double> zzz = x.contractions(il1,y,il2,1,false,false);
//cout <<"zzz names = "<<zzz.names<<endl;
z.add_permuted_contractions("",x,y,1,0,false,false);
zz.copyonwrite();
for(int k=0; k<nn; ++k) for(int l=0; l<nn; ++l) for(int m=0; m<nn; ++m) for(int n=0; n<nn; ++n)
{
double s=0;
for(int i=0; i<nn; ++i) for(int j=0; j<nn; ++j) s += x(i,j,k,l)*y(m,n,j,i);
zz.lhs(m,n,k,l) = s;
//cout <<"test "<<k<<" "<<l<<" "<<m<<" "<<n<<" "<<zz(k,l,m,n)<<" "<<zzz(m,n,k,l)<< " : "<<z(m,n,k,l) <<endl;
}
cout <<"Error = "<<(z-zz).norm()<<endl;
}
if(0)
{
int nn;

21
tensor.cc
View File

@@ -2107,44 +2107,37 @@ if(antinames.size()<tmpnames.size())
antinames[lastname] = tmpnames[j];
}
}
std::cout <<"final antisymmmetrizer names and groups"<<antinames<<antigroups;
//std::cout <<"final antisymmmetrizer names and groups"<<antinames<<antigroups;
//std::cout <<"LHS names = "<<names<<std::endl;
//std::cout <<"TMP names = "<<tmpnames<<std::endl;
//prepare the antisymmetrizer
PermutationAlgebra<int,int> pa = general_antisymmetrizer(antigroups,-2,true);
std::cout <<"initial antisymmetrizer = "<<pa;
//std::cout <<"initial antisymmetrizer = "<<pa;
//find permutation between antisym and TMP index order
NRPerm<int> antiperm=find_indexperm(antinames,tmpnames);
std::cout<<"permutation from rhs to antisymmetrizer = "<<antiperm<<std::endl;
//std::cout<<"permutation from rhs to antisymmetrizer = "<<antiperm<<std::endl;
//conjugate the PA by antiperm or its inverse
pa= pa.conjugated_by(antiperm,true);//@@@ or false?
pa= pa.conjugated_by(antiperm,true);
//find permutation which will bring indices of tmp to the order as in *this: this->names[i] == tmpnames[p[i]]
NRPerm<int> basicperm=find_indexperm(names,tmpnames);
std::cout <<"permutation from rhs to lhs = "<<basicperm<<std::endl;
//@@@PermutationAlgebra<int,T> pb = basicperm*pa; //for apply_permutation_algebra(tmp,pb,false,(T)1,beta);
PermutationAlgebra<int,T> pb = basicperm.inverse()*pa;
//@@@ OR PermutationAlgebra<int,T> pb = basicperm.inverse()*pa; apply_permutation_algebra(tmp,pb,true,(T)1,beta);
//std::cout <<"permutation from rhs to lhs = "<<basicperm<<std::endl;
//save some work if the PA is trivial
//save some work if the PA is trivial - contract only
if(pb.is_identity())
{
std::cout <<"simplified version\n";
addcontractions(rhs1,il1,rhs2,il2,alpha,beta,false,conjugate1,conjugate2);
return;
}
std::cout <<"full version\n";
//create an intermediate contracted tensir and the permute it
//create an intermediate contracted tensor and the permute it
Tensor<T> tmp=rhs1.contractions(il1,rhs2,il2,alpha,conjugate1,conjugate2);
if(rank()!=tmp.rank()) laerror("rank mismatch in add_permuted_contractions");
if(tmp.names!=tmpnames) laerror("internal error in add_permuted_contractions");
//@@@apply_permutation_algebra(tmp,pb,false,(T)1,beta);
apply_permutation_algebra(tmp,pb,true,(T)1,beta);
}