src/external/lmfit/lmmin.h

   1 /*
   2  * Library:   lmfit (Levenberg-Marquardt least squares fitting)
   3  *
   4  * File:      lmmin.h
   5  *
   6  * Contents:  Declarations for Levenberg-Marquardt minimization.
   7  *
   8  * Copyright: Joachim Wuttke, Forschungszentrum Juelich GmbH (2004-2013)
   9  *
  10  * License:   see ../COPYING (FreeBSD)
  11  *
  12  * Homepage:  apps.jcns.fz-juelich.de/lmfit
  13  */
  14
  15 #ifndef LMMIN_H
  16 #define LMMIN_H
  17
  18 #include "lmstruct.h"
  19
  20 /*! \brief
  21  * Levenberg-Marquardt minimization.
  22  *
  23  *   This routine contains the core algorithm of our library.
  24  *
  25  *   It minimizes the sum of the squares of m nonlinear functions
  26  *   in n variables by a modified Levenberg-Marquardt algorithm.
  27  *   The function evaluation is done by the user-provided routine 'evaluate'.
  28  *   The Jacobian is then calculated by a forward-difference approximation.
  29  *
  30  *   Parameters:
  31  *
  32  * \param[in] n_par The number of variables (INPUT, positive integer).
  33  * \param par The parameters to be fitted
  34  *      x is the solution vector (INPUT/OUTPUT, array of length n).
  35  *        On input it must be set to an estimated solution.
  36  *        On output it yields the final estimate of the solution.
  37  *
  38  *      m is the number of functions to be minimized (INPUT, positive integer).
  39  *        It must fulfill m>=n.
  40  *
  41  *      data is a pointer that is ignored by lmmin; it is however forwarded
  42  *        to the user-supplied functions evaluate and printout.
  43  *        In a typical application, it contains experimental data to be fitted.
  44  *
  45  *      evaluate is a user-supplied function that calculates the m functions.
  46  *        Parameters:
  47  *          n, x, m, data as above.
  48  *          fvec is an array of length m; on OUTPUT, it must contain the
  49  *            m function values for the parameter vector x.
  50  *          userbreak is an integer pointer. When *userbreak is set to a
  51  *            nonzero value, lmmin will terminate.
  52  *
  53  *      control contains INPUT variables that control the fit algorithm,
  54  *        as declared and explained in lmstruct.h
  55  *
  56  *      status contains OUTPUT variables that inform about the fit result,
  57  *        as declared and explained in lmstruct.h
  58  */
  59 void lmmin( const int n_par, double *par, const int m_dat, const void *data,
  60             void (*evaluate) (const double *par, const int m_dat, const void *data,
  61                               double *fvec, int *userbreak),
  62             const lm_control_struct *control, lm_status_struct *status );
  63
  64 #endif /* LMMIN_H */