implementation of permutations in progress

.gitignore

@@ -52,4 +52,5 @@ libla.la
 t
 test
 *.tar.bz2
+.*.swp
 # CVS default ignores end

Makefile.am

@@ -1,6 +1,6 @@
 lib_LTLIBRARIES = libla.la
 include_HEADERS = vecmat3.h quaternion.h fortran.h cuda_la.h auxstorage.h  davidson.h   laerror.h    mat.h          qsort.h             vec.h bisection.h   diis.h       la.h         noncblas.h     smat.h bitvector.h   fourindex.h  la_traits.h  nonclass.h     sparsemat.h sparsesmat.h csrmat.h conjgrad.h    gmres.h      matexp.h     permutation.h  
-libla_la_SOURCES = quaternion.cc vecmat3.cc vec.cc mat.cc smat.cc sparsemat.cc sparsesmat.cc csrmat.cc laerror.cc noncblas.cc  bitvector.cc strassen.cc nonclass.cc cuda_la.cc fourindex.cc
+libla_la_SOURCES = quaternion.cc vecmat3.cc vec.cc mat.cc smat.cc sparsemat.cc sparsesmat.cc csrmat.cc laerror.cc noncblas.cc  bitvector.cc strassen.cc nonclass.cc cuda_la.cc fourindex.cc permutation.cc
 check_PROGRAMS = t test
 t_SOURCES = t.cc t2.cc 
 test_SOURCES = test.cc

configure.ac

@@ -1,7 +1,7 @@
 #                                               -*- Autoconf -*-
 # Process this file with autoconf to produce a configure script.
 
-AC_PREREQ([2.63])
+AC_PREREQ([2.71])
 AC_INIT([libla],[1.1],[jiri@pittnerovi.com])
 AC_CONFIG_HEADERS([config.h])
 AC_CONFIG_MACRO_DIR([m4])
@@ -12,7 +12,7 @@ LT_INIT
 
 # Checks for programs.
 AC_PROG_CXX
-AC_PROG_LIBTOOL
+LT_INIT
 AC_PROG_CC
 #AC_PROG_RANLIB obsoleted by libtool
 AC_LANG(C++)

permutation.cc

@@ -0,0 +1,68 @@
+/*
+    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>;
+}

permutation.h

@@ -1,6 +1,6 @@
 /*
     LA: linear algebra C++ interface library
-    Copyright (C) 2008 Jiri Pittner <jiri.pittner@jh-inst.cas.cz> or <jiri@pittnerovi.com>
+    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
@@ -15,17 +15,46 @@
     You should have received a copy of the GNU General Public License
     along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
+
+
 #ifndef _PERMUTATION_H
 #define _PERMUTATION_H
+
+#include "la_traits.h"
+#include "vec.h"
+#include "mat.h"
+
+//permutations are always numbered from 1; offset is employed when applied to vectors and matrices
+
 namespace LA {
+
 template <typename T>
-const NRVec<T> inversepermutation(const NRVec<T> &p, const T offset=0)
+class NRPerm : public NRVec_from1<T> {
-{
+public:
-int n=p.size();
+	//basic constructors
-NRVec<T> q(n);
+	NRPerm(): NRVec_from1<T>() {};
-if(!offset) for(int i=0; i<n; ++i) q[p[i]]=i;
+	NRPerm(const int n) : NRVec_from1<T>(n) {};
-else for(int i=0; i<n; ++i) q[p[i]-offset]=i+offset;
+	NRPerm(const NRVec_from1<T> &rhs): NRVec_from1<T>(rhs) {};
-return q;
+	NRPerm(const T &a, const int n): NRVec_from1<T>(a, n) {};
-}
+        NRPerm(const T *a, const int n): NRVec_from1<T>(a, n) {};
+
+	//specific operations
+	bool is_valid() const; //is it really a permutation
+	NRPerm inverse() const;
+	NRPerm operator*(const NRPerm rhs) const;
+
+	//TODO:
+	//@@@conjugate by q
+	//@@@permgener
+	//@@@lex rank
+	//@@@next permutation
+	//@@@inversion tables
+	//@@@parity
+	//@@@conversion to cycle structure and back
+};
+
+
+
+
 }//namespace
 #endif