69 lines
1.7 KiB
C++
69 lines
1.7 KiB
C++
/*
|
|
LA: linear algebra C++ interface library
|
|
Copyright (C) 2021 Jiri Pittner <jiri.pittner@jh-inst.cas.cz> or <jiri@pittnerovi.com>
|
|
|
|
This program is free software: you can redistribute it and/or modify
|
|
it under the terms of the GNU General Public License as published by
|
|
the Free Software Foundation, either version 3 of the License, or
|
|
(at your option) any later version.
|
|
|
|
This program is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
GNU General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with this program. If not, see <http://www.gnu.org/licenses/>.
|
|
*/
|
|
|
|
#include "permutation.h"
|
|
namespace LA {
|
|
|
|
template <typename T>
|
|
bool NRPerm<T>::is_valid() const
|
|
{
|
|
T n = this->size();
|
|
if(n<0) return 0;
|
|
NRVec_from1<T> used(n);
|
|
used.clear();
|
|
for(T i=1; i<=n; ++i)
|
|
{
|
|
T x= (*this)[i];
|
|
if(x<1||x>n) return 0;
|
|
used[x] += 1;
|
|
}
|
|
for(T i=1; i<=n; ++i) if(used[i]!=1) return 0;
|
|
return 1;
|
|
}
|
|
|
|
template <typename T>
|
|
NRPerm<T> NRPerm<T>::inverse() const
|
|
{
|
|
NRPerm<T> q(this->size());
|
|
for(T i=1; i<=this->size(); ++i) q[(*this)[i]]=i;
|
|
return q;
|
|
}
|
|
|
|
|
|
template <typename T>
|
|
NRPerm<T> NRPerm<T>::operator*(const NRPerm<T> q) const
|
|
{
|
|
T n=this->size();
|
|
if(n!=q.size()) laerror("product of incompatible permutations");
|
|
NRPerm<T> r(n);
|
|
for(T i=1; i<=n; ++i) r[i] = q[(*this)[i]];
|
|
return r;
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
|
|
/***************************************************************************//**
|
|
* forced instantization in the corresponding object file
|
|
******************************************************************************/
|
|
template class NRPerm<int>;
|
|
}
|