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continueing on partitions

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Jiri Pittner
2021-05-24 22:12:39 +02:00
parent 7d9fc46784
commit 40fe368c31
3 changed files with 44 additions and 7 deletions
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31
permutation.cc
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@@ -746,7 +746,7 @@ PERM_RANK_TYPE r=factorial(n);
for(int i=1; i<=n; ++i)
{
T m=(*this)[i];
if(i>1 && m>0) r/=ipow(i,m);
if(i>1 && m>0) r/=longpow(i,m);
if(m>1) r/=factorial(m);
}
return r;
@@ -770,6 +770,33 @@ return factorial(n)/prod;
}
/*hammermesh eq 10-25, highest weight == generalized partition of r into n parts*/
template <typename T>
PERM_RANK_TYPE Partition<T>::Un_irrep_dim(const int n) const
{
#ifdef DEBUG
if(!this->is_valid()) laerror("operation with an invalid partition");
#endif
std::cout<<"TEST "<<nparts()<<" "<<n<<std::endl;
if(nparts()>n) return 0; //too antisymmetric partition
int i,j;
double prod;
int r=this->size();
NRVec_from1<int> p(n);
for(i=1;i<=n;i++) p[i]= (i<=r?(*this)[i]:0)+n-i;
std::cout<<"TEST "<<p<<std::endl;
prod=1;
for(j=n;j>=2;j--)
{
for(i=1;i<j;i++) prod*= (p[i]-p[j]);
prod /= factorial(j-1); //can be fractional in the intermediate steps - needs double
}
return (PERM_RANK_TYPE) (prod+0.2);
}
template <typename T>
Partition<T> Partition<T>::adjoint() const
{
@@ -802,7 +829,7 @@ this->clear();
for(int i=1; i<=nparts; ++i) (*this)[i]=x[i].size();
}
PERM_RANK_TYPE ipow(PERM_RANK_TYPE x, int i)
PERM_RANK_TYPE longpow(PERM_RANK_TYPE x, int i)
{
if(i<0) return 0;
PERM_RANK_TYPE y=1;