include/nrjac.h

   1 /*
   2  *
   3  *                This source code is part of
   4  *
   5  *                 G   R   O   M   A   C   S
   6  *
   7  *          GROningen MAchine for Chemical Simulations
   8  *
   9  *                        VERSION 3.2.0
  10  * Written by David van der Spoel, Erik Lindahl, Berk Hess, and others.
  11  * Copyright (c) 1991-2000, University of Groningen, The Netherlands.
  12  * Copyright (c) 2001-2004, The GROMACS development team,
  13  * check out http://www.gromacs.org for more information.
  14
  15  * This program is free software; you can redistribute it and/or
  16  * modify it under the terms of the GNU General Public License
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  35
  36 #ifndef _nrjac_h
  37 #define _nrjac_h
  38
  39 #include "typedefs.h"
  40
  41 #ifdef __cplusplus
  42 extern "C" {
  43 #endif
  44
  45 void jacobi(double **a,int n,double d[],double **v,int *nrot);
  46 /*
  47  * real   **omega = input matrix a[0..n-1][0..n-1] must be symmetric
  48  * int     natoms = number of rows and columns
  49  * real      NULL = d[0]..d[n-1] are the eigenvalues of a[][]
  50  * real       **v = v[0..n-1][0..n-1] the eigenvectors:
  51  *                                    v[i][j] is component i of vector j
  52  * int      *irot = number of jacobi rotations
  53  */
  54
  55 int m_inv_gen(real **m,int n,real **minv);
  56 /* Produces minv, a generalized inverse of m.
  57  * Inversion is done via diagonalization,
  58  * eigenvalues smaller than 1e-6 times the average diagonal element
  59  * are assumed to be zero.
  60  * For zero eigenvalues 1/eigenvalue is set to zero for the inverse matrix.
  61  * Returns the number of zero eigenvalues.
  62  */
  63
  64 #ifdef __cplusplus
  65 }
  66 #endif
  67
  68 #endif