// -*- C++ -*-
// SymTensor.h: Symmetric tensor objects (containing six doubles).
//
// Copyright (C) 2008 Jakob Schiotz and Center for Individual
// Nanoparticle Functionality, Department of Physics, Technical
// University of Denmark. Email: schiotz@fysik.dtu.dk
//
// This file is part of Asap version 3.
// Asap is released under the GNU Lesser Public License (LGPL) version 3.
// However, the parts of Asap distributed within the OpenKIM project
// (including this file) are also released under the Common Development
// and Distribution License (CDDL) version 1.0.
//
// This program is free software: you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public License
// version 3 as published by the Free Software Foundation. Permission
// to use other versions of the GNU Lesser General Public License may
// granted by Jakob Schiotz or the head of department of the
// Department of Physics, Technical University of Denmark, as
// described in section 14 of the GNU General Public License.
//
// 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
// and the GNU Lesser Public License along with this program. If not,
// see .
#ifndef _SYMTENSOR_H
#define _SYMTENSOR_H
#include
using std::istream;
using std::ostream;
namespace ASAPSPACE {
class SymTensor
{
public:
SymTensor() {};
/// Set to zero
void clear();
/// const indexing
double operator[](int n) const;
/// Non-const indexing
double& operator[](int n);
/// Add a SymTensor to this one.
SymTensor& operator+=(const SymTensor& v);
/// Multiply a SymTensor with a scalar.
SymTensor& operator*=(double x);
/// Print a SymTensor
friend ostream& operator<<(ostream& out, const SymTensor& v);
private:
double x[6]; ///< The actual data.
};
inline void SymTensor::clear()
{
x[0] = x[1] = x[2] = x[3] = x[4] = x[5] = 0.0;
}
inline double SymTensor::operator[](int n) const
{
return x[n];
}
inline double& SymTensor::operator[](int n)
{
return x[n];
}
inline SymTensor& SymTensor::operator+=(const SymTensor& v)
{
x[0] += v.x[0]; x[1] += v.x[1]; x[2] += v.x[2];
x[3] += v.x[3]; x[4] += v.x[4]; x[5] += v.x[5];
return *this;
}
inline SymTensor& SymTensor::operator*=(double v)
{
x[0] *= v; x[1] *= v; x[2] *= v;
x[3] *= v; x[4] *= v; x[5] *= v;
return *this;
}
inline ostream& operator<<(ostream& out, const SymTensor& v)
{
out << "(" << v[0] << ", " << v[1] << ", " << v[2] << ", "
<< v[3] << ", " << v[4] << ", " << v[5] << ")";
return out;
}
} // end namespace
#endif // _SYMTENSOR_H