cantera/include/cantera/oneD/MultiNewton.h

86 lines
2.5 KiB
C++

//! @file MultiNewton.h
// This file is part of Cantera. See License.txt in the top-level directory or
// at http://www.cantera.org/license.txt for license and copyright information.
#ifndef CT_MULTINEWTON_H
#define CT_MULTINEWTON_H
#include "MultiJac.h"
namespace Cantera
{
/**
* Newton iterator for multi-domain, one-dimensional problems.
* Used by class OneDim.
* @ingroup onedim
*/
class MultiNewton
{
public:
MultiNewton(int sz);
virtual ~MultiNewton() {};
size_t size() {
return m_n;
}
//! Compute the undamped Newton step. The residual function is evaluated
//! at `x`, but the Jacobian is not recomputed.
void step(doublereal* x, doublereal* step,
OneDim& r, MultiJac& jac, int loglevel);
/**
* Return the factor by which the undamped Newton step 'step0'
* must be multiplied in order to keep all solution components in
* all domains between their specified lower and upper bounds.
*/
doublereal boundStep(const doublereal* x0, const doublereal* step0,
const OneDim& r, int loglevel);
/**
* On entry, step0 must contain an undamped Newton step for the solution x0.
* This method attempts to find a damping coefficient such that the next
* undamped step would have a norm smaller than that of step0. If
* successful, the new solution after taking the damped step is returned in
* x1, and the undamped step at x1 is returned in step1.
*/
int dampStep(const doublereal* x0, const doublereal* step0,
doublereal* x1, doublereal* step1, doublereal& s1,
OneDim& r, MultiJac& jac, int loglevel, bool writetitle);
//! Compute the weighted 2-norm of `step`.
doublereal norm2(const doublereal* x, const doublereal* step,
OneDim& r) const;
/**
* Find the solution to F(X) = 0 by damped Newton iteration. On entry, x0
* contains an initial estimate of the solution. On successful return, x1
* contains the converged solution.
*/
int solve(doublereal* x0, doublereal* x1, OneDim& r, MultiJac& jac,
int loglevel);
/// Set options.
void setOptions(int maxJacAge = 5) {
m_maxAge = maxJacAge;
}
/// Change the problem size.
void resize(size_t points);
protected:
//! Work arrays of size #m_n used in solve().
vector_fp m_x, m_stp, m_stp1;
int m_maxAge;
//! number of variables
size_t m_n;
doublereal m_elapsed;
};
}
#endif