generic/solver/lsode.c

/*  ASCEND modelling environment
    Copyright 1997, Carnegie Mellon University
    Copyright (C) 2006 Carnegie Mellon University

    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 2, 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, write to the Free Software
    Foundation, Inc., 59 Temple Place - Suite 330,
    Boston, MA 02111-1307, USA.
*//**
    @file
    LSODE integrator.

    (old implementation notes:)

    As fortran io is unreliably portable (vc5+digital fortran)
    we have converted xerrwv to xascwv provided here.

    The lsode interface variable t is actually an array of
    2 doubles rather than just 1. The first is the the one
    used by lsode. The second is used by LSODE_FEX to tell
    what the last time it was called was. This is so the
    C driver can tell if it needs to resolve d to compute
    observation variables. If x[0]==x[1] we save ourselves
    a solve.

    @NOTE The above doesn't work since lsode doesn't use the same t internally
    that we hand it.

*//*
    by Kirk Abbott and Ben Allan
    Created: 1/94
    Version: $Revision: 1.29 $
    Version control file: $RCSfile: Lsode.c,v $
    Date last modified: $Date: 2000/01/25 02:26:31 $
    Last modified by: $Author: ballan $
 */

#ifndef NO_SIGNAL_TRAPS
#include <signal.h>
#include <setjmp.h>
#endif /* NO_SIGNAL_TRAPS */

#include <utilities/ascConfig.h>
#include <utilities/error.h>
#include <compiler/instance_enum.h>
#include <utilities/ascSignal.h>
#include <utilities/ascMalloc.h>
#include <utilities/ascPanic.h>

#include "slv_types.h"
#include "mtx.h"
#include "rel.h"
#include "var.h"
#include "discrete.h"
#include "conditional.h"
#include "bnd.h"
#include "logrel.h"
#include "slv_common.h"
#include "linsol.h"
#include "linsolqr.h"
#include "slv_client.h"

#include "integrator.h"
#include "lsode.h"

/*
#include "Sensitivity.h"
*//* see the packages dir */

#ifndef lint
static CONST char LsodeID[] = "$Id: Lsode.c,v 1.29 2000/01/25 02:26:31 ballan Exp $";
#endif


/*
 *  NOUNDERBARS --> FORTRAN compiler naming convention for subroutine
 *  is wierd. WIN32/CRAY is treated as special case
 */
#ifdef APOLLO
#define NOUNDERBARS TRUE
#endif
#ifdef _HPUX_SOURCE
#define NOUNDERBARS TRUE
#endif
/* AIX xlf will not suffix an underbar on a symbol
 * unless xlf is given the ``-qextname'' option
 */
#ifdef _AIX
#define NOUNDERBARS TRUE
#endif

#ifdef NOUNDERBARS
#define LSODE lsode
#define LSODE_JEX jex
#define LSODE_FEX fex
#define GETCOMMON get_lsode_common
#define XASCWV xascwv
#else
/* sun, __alpha, __sgi, ... */
#define LSODE lsode_
#define LSODE_JEX jex_
#define LSODE_FEX fex_
#define GETCOMMON get_lsode_common_
#define XASCWV xascwv_
#endif

#if defined(CRAY) || (defined(__WIN32__) && !defined(__MINGW32_VERSION))
#undef LSODE
#undef LSODE_JEX
#undef LSODE_FEX
#undef GETCOMMON
#undef XASCWV
#define XASCWV XASCWV
#define LSODE LSODE
#define LSODE_JEX JEX
#define LSODE_FEX FEX
#define GETCOMMON GET_LSODE_COMMON
#endif

#define DOTIME FALSE

/* definitions of lsode supported children of atoms, etc */
/********************************************************************/
/* solver_var children expected for state variables */
static symchar *g_symbols[2];
#define STATERTOL g_symbols[0]
#define STATEATOL g_symbols[1]
static
void InitTolNames(void)
{
  STATERTOL = AddSymbol("ode_rtol");
  STATEATOL = AddSymbol("ode_atol");
}

/**
    Because LSODE doesn't seem to make an allowance for 'client data' we
    have to store this as a 'local global' and fish it out when we're in the
    callbacks.
*/
IntegratorSystem *l_lsode_blsys;

enum Lsode_enum {
  lsode_none,               /* true on first call */
  lsode_function, lsode_derivative, /* functions or gradients done */
  lsode_sparse, lsode_dense,        /* what type of backend should we */
  lsode_band,               /* use for the integrator */
  lsode_ok, lsode_nok           /* bad return from func or grad */
};

static struct Lsode_Data {
  enum Lsode_enum lastcall;     /* type of last call; func or grad */
  enum Lsode_enum status;       /* solve status */
  int partitioned;          /* partioned func evals or not */
} lsodesys = {lsode_none, lsode_ok, 1};


/*--------------------------
  Data space for use by LSODE
*/
typedef struct{
  long n_eqns;                     /**< dimension of state vector */
  int *input_indices;              /**< vector of state vars indexes */
  int *output_indices;             /**< vector of derivative var indexes */
  struct var_variable **y_vars;    /**< NULL terminated list of states vars */
  struct var_variable **ydot_vars; /**< NULL terminated list of derivative vars*/
  struct rel_relation **rlist;     /**< NULL terminated list of relevant rels
                                        to be differentiated */
  double **dydx_dx;                /**< change in derivatives wrt states
                                        I prefer to call this: d(ydot)/dy */
} IntegratorLsodeData;


/*----------------------------
  Function types that LSODE wants to use
*/

/**
    Type of function used to evaluate derivative system.
*/
typedef void LsodeEvalFn(int *, double *, double *, double *);

/**
    Type of function used to evaluate jacobian system.
*/
typedef void LsodeJacobianFn(int *, double *, double *, int *, int *, double *, int *);

/*----------------------------
  forward declarations
*/

int integrator_lsode_setup_diffs(IntegratorSystem *blsys);
static double **lsode_densematrix_create(int nrows, int ncols);
static void lsode_densematrix_destroy(double **matrix,int nrows);

/**
    void LSODE(&fex, &neq, y, &x, &xend, &itol, reltol, abtol, &itask,
        &istate, &iopt ,rwork, &lrw, iwork, &liw, &jex, &mf);

    This is a prototype for the *fortran* LSODE function.

    No 'extern' here, so we want linker to complain if no static linkage.
 */
void LSODE(LsodeEvalFn*,int *neq ,double *y ,double *x
      ,double *xend
      ,int *itol ,double *reltol ,double *abtol
      ,int *itask ,int *istate ,int *iopt
      ,double *rwork ,int *lrw
      ,int *iwork ,int *liw
      ,LsodeJacobianFn *jex ,int *mf
);

/*------------------------------------------------------
  Memory allocation/free
*/

void integrator_lsode_create(IntegratorSystem *blsys){
    IntegratorLsodeData *d;
    d = ASC_NEW_CLEAR(IntegratorLsodeData);
    d->n_eqns=0;
    d->input_indices=NULL;
    d->output_indices=NULL;
    d->y_vars=NULL;
    d->ydot_vars=NULL;
    d->rlist=NULL;
    d->dydx_dx=NULL;
    blsys->enginedata=(void*)d;
    integrator_lsode_params_default(blsys);

}

/**
    Cleanup the data struct that belongs to LSODE
*/
void integrator_lsode_free(void *enginedata){
    IntegratorLsodeData d;
    d = *((IntegratorLsodeData *)enginedata);

    if(d.input_indices)ASC_FREE(d.input_indices);
    d.input_indices = NULL;

    if(d.output_indices)ASC_FREE(d.output_indices);
    d.output_indices = NULL;

    if(d.y_vars)ASC_FREE(d.y_vars);
    d.y_vars = NULL;

    if(d.ydot_vars)ASC_FREE(d.ydot_vars);
    d.ydot_vars = NULL;

    if(d.rlist)ASC_FREE(d.rlist);
    d.rlist =  NULL;

    if(d.dydx_dx)lsode_densematrix_destroy(d.dydx_dx, d.n_eqns);
    d.dydx_dx =  NULL;

    d.n_eqns = 0L;
}

/*------------------------------------------------------------------------------
    PARAMETERS
*/

enum ida_parameters{
    LSODE_PARAM_TIMING
    ,LSODE_PARAM_RTOLDEF
    ,LSODE_PARAM_ATOLDEF
    ,LSODE_PARAMS_SIZE
};

/**
    Here the full set of parameters is defined, along with upper/lower bounds,
    etc. The values are stuck into the blsys->params structure.

    @return 0 on success
*/
int integrator_lsode_params_default(IntegratorSystem *blsys){

    asc_assert(blsys!=NULL);
    asc_assert(blsys->engine==INTEG_LSODE);
    slv_parameters_t *p;
    p = &(blsys->params);

    slv_destroy_parms(p);

    if(p->parms==NULL){
        CONSOLE_DEBUG("params NULL");
        p->parms = ASC_NEW_ARRAY(struct slv_parameter, LSODE_PARAMS_SIZE);
        if(p->parms==NULL)return -1;
        p->dynamic_parms = 1;
    }else{
        asc_assert(p->num_parms == LSODE_PARAMS_SIZE);
        CONSOLE_DEBUG("reusing parm memory");
    }

    /* reset the number of parameters to zero so that we can check it at the end */
    p->num_parms = 0;

    slv_param_bool(p,LSODE_PARAM_TIMING
            ,(SlvParameterInitBool){{"timing"
            ,"Output timing statistics?",1,NULL
        }, TRUE}
    );

    slv_param_real(p,LSODE_PARAM_ATOLDEF
            ,(SlvParameterInitReal){{"atoldef"
            ,"Scalar absolute error tolerance",1
            ,"Default value of the scalar absolute error tolerance (for cases"
            " where not specified in oda_atol var property. See 'lsode.f' for"
            " details"
        }, 1e-6, DBL_MIN, DBL_MAX }
    );

    slv_param_real(p,LSODE_PARAM_RTOLDEF
            ,(SlvParameterInitReal){{"rtoldef"
            ,"Scalar relative error tolerance",1
            ,"Default value of the scalar relative error tolerance (for cases"
            " where not specified in oda_rtol var property. See 'lsode.f' for"
            " details"
        }, 1e-6, DBL_MIN, DBL_MAX }
    );

    asc_assert(p->num_parms == LSODE_PARAMS_SIZE);

    CONSOLE_DEBUG("Created %d params", p->num_parms);

    return 0;
}   

/*---------------------------------------------------------
  Couple of matrix methods...?
*/

static double **lsode_densematrix_create(int nrows, int ncols){
  int c;
  double **result;
  assert(nrows>0);
  assert(ncols>0);
  result = ASC_NEW_ARRAY(double *, nrows);
  for (c=0;c<nrows;c++) {
    result[c] = ASC_NEW_ARRAY_CLEAR(double, ncols);
  }
  return result;
}

static void lsode_densematrix_destroy(double **matrix,int nrows){
  int c;
  if (matrix) {
    for (c=0;c<nrows;c++) {
      if (matrix[c]) {
        ascfree((char *)matrix[c]);
      }
    }
    ascfree((char *)matrix);
  }
}

/*------------------------------------------------------------------------------
  PROBLEM ANALYSIS
*/

/**
    @TODO needs work. Assumes struct Instance* and struct var_variable*
    are synonymous, which demonstrates the need for a method to take
    an instance and ask the solvers for its global or local index
    if var and inst are decoupled.
*/
int integrator_lsode_setup_diffs(IntegratorSystem *blsys) {
    /* long n_eqns; */
    unsigned long nch,i;

    struct var_variable **vp;
    int *ip;

    IntegratorLsodeData *enginedata;
    enginedata = (IntegratorLsodeData *)blsys->enginedata;
    assert(enginedata!=NULL);

    assert(enginedata->n_eqns==blsys->n_y);

  /*
    Put the
    Let us now process what we consider *inputs* to the problem as
    far as ASCEND is concerned; i.e. the state vars or the y_vars's
    if you prefer.
  */
  nch = enginedata->n_eqns;


  vp = enginedata->y_vars;
  ip = enginedata->input_indices;
  for (i=0;i<nch;i++) {
    *vp = (struct var_variable *)blsys->y[i];
    *ip = var_sindex(*vp);
    vp++;
    ip++;
  }
  *vp = NULL;   /* terminate */

  /*
    Let us now go for the outputs, ie the derivative terms.
  */
  vp = enginedata->ydot_vars;
  ip = enginedata->output_indices;
  for (i=0;i<nch;i++) {
    *vp = (struct var_variable *)blsys->ydot[i];
    *ip = var_sindex(*vp);
    vp++;       /* dont assume that a var is synonymous with */
    ip++;       /* an Instance; that might/will change soon */
  }
  *vp = NULL;       /* terminate */

  return 0;
}

/**
    allocates, fills, and returns the atol vector based on LSODE

    State variables missing child ode_rtol will be defaulted to ATOLDEF
*/
static double *lsode_get_atol( IntegratorSystem *blsys) {

  struct Instance *tol;
  double *atoli;
  int i,len;

  len = blsys->n_y;
  atoli = ASC_NEW_ARRAY(double, blsys->n_y+1);
  if (atoli == NULL) {
    ERROR_REPORTER_HERE(ASC_PROG_ERR,"Insufficient memory");
    return atoli;
  }
  InitTolNames();
  for (i=0; i<len; i++) {
    tol = ChildByChar(var_instance(blsys->y[i]),STATEATOL);
    if (tol == NULL || !AtomAssigned(tol) ) {
      atoli[i] = SLV_PARAM_REAL(&(blsys->params),LSODE_PARAM_ATOLDEF);
      ERROR_REPORTER_HERE(ASC_PROG_WARNING,"Assuming atol = %3g"
        "for ode_atol child undefined for state variable %ld."
        ,atoli[i], blsys->y_id[i]
      );
    } else {
      atoli[i] = RealAtomValue(tol);
      CONSOLE_DEBUG("Using tolerance %3g for state variable %ld.",atoli[i], blsys->y_id[i]);
    }
  }
  atoli[len] = SLV_PARAM_REAL(&(blsys->params),LSODE_PARAM_ATOLDEF); /* not sure why this one...? */
  return atoli;
}

/**
    Allocates, fills, and returns the rtol vector based on LSODE

    State variables missing child ode_rtol will be defaulted to RTOLDEF
*/
static double *lsode_get_rtol( IntegratorSystem *blsys) {

  struct Instance *tol;
  double *rtoli;
  int i,len;

  len = blsys->n_y;
  rtoli = ASC_NEW_ARRAY(double, blsys->n_y+1);
  if (rtoli == NULL) {
    ERROR_REPORTER_HERE(ASC_PROG_ERR,"Insufficient memory");
    return rtoli;
  }
  InitTolNames();
  for (i=0; i<len; i++) {
    tol = ChildByChar(var_instance(blsys->y[i]),STATERTOL);
    if (tol == NULL || !AtomAssigned(tol) ) {
      rtoli[i] = SLV_PARAM_REAL(&(blsys->params),LSODE_PARAM_RTOLDEF);

      ERROR_REPORTER_HERE(ASC_PROG_WARNING,"Assuming rtol = %3g"
        "for ode_rtol child undefined for state variable %ld."
        ,rtoli[i], blsys->y_id[i]
      );

    } else {
      rtoli[i] = RealAtomValue(tol);
    }
  }
  rtoli[len] = SLV_PARAM_REAL(&(blsys->params),LSODE_PARAM_RTOLDEF);
  return rtoli;
}

/*
    Write out a a status message based on the istate parameter.
*/
static void lsode_write_istate( int istate) {
  switch (istate) {
  case -1:
    FPRINTF(ASCERR,"Excess steps taken on this call (perhaps wrong MF).");
    break;
  case -2:
    FPRINTF(ASCERR,"Excess accuracy requested (tolerances too small).");
    break;
  case -3:
    FPRINTF(ASCERR,"Illegal input detected (see console).");
    break;
  case -4:
    FPRINTF(ASCERR,"Repeated error test failures (check all inputs).");
    break;
  case -5:
    FPRINTF(ASCERR,"Repeated convergence failures (perhaps bad Jacobian supplied, or wrong choice of MF or tolerances).");
    break;
  case -6:
    FPRINTF(ASCERR,"Error weight became zero during problem (solution component i vanished, and atol or atol(i) = 0).");
    break;
  case -7:
    FPRINTF(ASCERR,"Interrupted? User cancelled operation?");
    break;
  default:
    FPRINTF(ASCERR,"Unknown 'istate' error code %d from LSODE.",istate);
    break;
  }
}

/**
    Free memory allocated for the LSODE, but first check.
*/
static void lsode_free_mem(double *y, double *reltol, double *abtol, double *rwork,
                    int *iwork, double *obs, double *dydx)
{
  if (y != NULL) {
    ascfree((double *)y);
  }
  if (reltol != NULL) {
    ascfree((double *)reltol);
  }
  if (abtol != NULL) {
    ascfree((double *)abtol);
  }
  if (rwork != NULL) {
    ascfree((double *)rwork);
  }
  if (iwork != NULL) {
    ascfree((int *)iwork);
  }
  if (obs != NULL) {
    ascfree((double *)obs);
  }
  if (dydx != NULL) {
    ascfree((double *)dydx);
  }
}

/*
 *********************************************************************
 * This code is provided for the benefit of a temporary
 * fix for the derivative problem in Lsode.
 * The proper permanent fix for lsode is to dump it in favor of
 * cvode or dassl.
 * Extended 7/95 baa to deal with linsolqr and lsode.
 * It is assumed the system has been solved at the current point.
 *********************************************************************
 */
int lsode_derivatives(slv_system_t sys, double **dy_dx,
                       int *inputs_ndx_list, int ninputs,
                       int *outputs_ndx_list, int noutputs)
{
  static int n_calls = 0;
  linsolqr_system_t lqr_sys;    /* stuff for the linear system & matrix */
  mtx_matrix_t mtx;
  int32 capacity;
  real64 *scratch_vector = NULL;
  int result=0;

  (void)NumberFreeVars(NULL);       /* used to re-init the system */
  (void)NumberIncludedRels(NULL);   /* used to re-init the system */
  if (!sys) {
    FPRINTF(stderr,"The solve system does not exist !\n");
    return 1;
  }

  result = Compute_J(sys);
  if (result) {
    FPRINTF(stderr,"Early termination due to failure in calc Jacobian\n");
    return 1;
  }

  lqr_sys = slv_get_linsolqr_sys(sys);  /* get the linear system */
  if (lqr_sys==NULL) {
    FPRINTF(stderr,"Early termination due to missing linsolqr system.\n");
    return 1;
  }
  mtx = slv_get_sys_mtx(sys);   /* get the matrix */
  if (mtx==NULL) {
    FPRINTF(stderr,"Early termination due to missing mtx in linsolqr.\n");
    return 1;
  }
  capacity = mtx_capacity(mtx);
  scratch_vector = ASC_NEW_ARRAY_CLEAR(real64,capacity);
  linsolqr_add_rhs(lqr_sys,scratch_vector,FALSE);

  result = LUFactorJacobian(sys);
  if (result) {
    FPRINTF(stderr,"Early termination due to failure in LUFactorJacobian\n");
    goto error;
  }
  result = Compute_dy_dx_smart(sys, scratch_vector, dy_dx,
                               inputs_ndx_list, ninputs,
                               outputs_ndx_list, noutputs);

  linsolqr_remove_rhs(lqr_sys,scratch_vector);
  if (result) {
    FPRINTF(stderr,"Early termination due to failure in Compute_dy_dx\n");
    goto error;
  }

 error:
  n_calls++;
  if (scratch_vector) {
    ascfree((char *)scratch_vector);
  }
  return result;
}

/**
    The current way that we are getting the derivatives (if the problem
    was solved partitioned) messes up the slv_system so that we *have*
    to do a *presolve* rather than a simply a *resolve* before doing
    function calls.  This code below attempts to handle these cases.
*/
static void LSODE_FEX( int *n_eq ,double *t ,double *y ,double *ydot)
{
  slv_status_t status;

  /*  slv_parameters_t parameters; pity lsode doesn't allow error returns */
  /* int i; */
  unsigned long ok;

#if DOTIME
  double time1,time2;
#endif

  /* CONSOLE_DEBUG("Calling for a function evaluation"); */

#if DOTIME
  CONSOLE_DEBUG("Calling for a function evaluation");
  time1 = tm_cpu_time();
#endif

  /*
    t[1]=t[0]; can't do this. lsode calls us with a different t than the t we sent in.
  */
  integrator_set_t(l_lsode_blsys, t[0]);
  integrator_set_y(l_lsode_blsys, y);

#if DOTIME
  time2 = tm_cpu_time();
#endif

  switch(lsodesys.lastcall) {
  case lsode_none:      /* first call */
    CONSOLE_DEBUG("FIRST CALL...");

  case lsode_derivative:
    if (lsodesys.partitioned) {
      /* CONSOLE_DEBUG("PRE-SOLVE"); */
      slv_presolve(l_lsode_blsys->system);
    } else {
      /** @TODO this doesn't ever seem to be called */
      CONSOLE_DEBUG("RE-SOLVE");
      slv_resolve(l_lsode_blsys->system);
    }
    break;
  default:
  case lsode_function:
    slv_resolve(l_lsode_blsys->system);
    break;
  }

  slv_solve(l_lsode_blsys->system);
  slv_get_status(l_lsode_blsys->system, &status);
  /* pass the solver status to the integrator */
  ok = integrator_checkstatus(status);

#if DOTIME
  time2 = tm_cpu_time() - time2;
#endif

  if (!ok) {
    ERROR_REPORTER_HERE(ASC_PROG_ERR,"Failed to solve for derivatives");
    /*
    ERROR_REPORTER_START_HERE(ASC_PROG_ERR);
    FPRINTF(ASCERR,"Unable to compute the vector of derivatives with the following values for the state variables:\n");
    for (i = 0; i< *n_eq; i++) {
      FPRINTF(ASCERR,"y[%4d] = %f\n",i, y[i]);
    }
    error_reporter_end_flush();
    */
    lsodesys.status = lsode_nok;
  } else {
    lsodesys.status = lsode_ok;
  }
  integrator_get_ydot(l_lsode_blsys, ydot);

  lsodesys.lastcall = lsode_function;
#if DOTIME
  time1 = tm_cpu_time() - time1;
  CONSOLE_DEBUG("Function evalulation has been completed in time %g. True function call  time = %g",time1,time2);
#endif
}

/**
    Evaluate the jacobian
*/
static void LSODE_JEX(int *neq ,double *t, double *y,
                      int *ml ,int *mu ,double *pd, int *nrpd)
{
  int nok = 0;
  int i,j;

  IntegratorLsodeData enginedata=*((IntegratorLsodeData *)l_lsode_blsys->enginedata);

  UNUSED_PARAMETER(t);
  UNUSED_PARAMETER(y);
  UNUSED_PARAMETER(ml);
  UNUSED_PARAMETER(mu);

  /* CONSOLE_DEBUG("Calling for a gradient evaluation"); */
#if DOTIME
  double time1;

  CONSOLE_DEBUG("Calling for a gradient evaluation");
  time1 = tm_cpu_time();
#endif
  /*
   * Make the real call.
   */
  nok = lsode_derivatives(l_lsode_blsys->system
        , enginedata.dydx_dx
        , enginedata.input_indices
        , *neq
        , enginedata.output_indices
        , *nrpd
  );

  if (nok) {
    ERROR_REPORTER_HERE(ASC_PROG_ERR,"Error in computing the derivatives for the system. Failing...");
    lsodesys.status = lsode_nok;
    lsodesys.lastcall = lsode_derivative;
    return;
  } else {
    lsodesys.status = lsode_ok;
    lsodesys.lastcall = lsode_derivative;
  }
  /*
    Map data from C based matrix to Fortan matrix.
    We will send in a column major ordering vector for pd.
  */
  for (j=0;j<*neq;j++) { /* loop through columnns */
    for (i=0;i<*nrpd;i++){ /* loop through rows */
      /* CONSOLE_DEBUG("JAC[r=%d,c=%d]=%f",i,j,enginedata.dydx_dx[i][j]); */
      *pd++ = enginedata.dydx_dx[i][j];
    }
  }

#if DOTIME
  time1 = tm_cpu_time() - time1;
  CONSOLE_DEBUG("Time to do gradient evaluation %g",time1);
#endif

  return;
}

/**
    The public function: here we do the actual integration, I guess.
*/
int integrator_lsode_solve(IntegratorSystem *blsys
        , unsigned long start_index, unsigned long finish_index
){
    slv_status_t status;
    slv_parameters_t params;
    IntegratorLsodeData *d;

    double x[2];
    double xend,xprev;
    unsigned long nsamples, neq;
    long nobs;
    int  itol, itask, mf, lrw, liw;
    unsigned long index;
    int istate, iopt;
    double * rwork;
    int * iwork;
    double *y, *abtol, *reltol, *obs, *dydx;
    int my_neq;
    FILE *y_out =NULL;
    FILE *obs_out =NULL;
    int reporterstatus;

    /* store the local variable so that we can get at stuff from inside LSODE_FEX. */
    l_lsode_blsys = blsys;

    d = (IntegratorLsodeData *)(blsys->enginedata);

    /* the numer of equations must be equal to blsys->n_y, the number of states */
    d->n_eqns = blsys->n_y;
    assert(d->n_eqns>0);

    d->input_indices = ASC_NEW_ARRAY_CLEAR(int, d->n_eqns);
    d->output_indices = ASC_NEW_ARRAY_CLEAR(int, d->n_eqns);
    d->dydx_dx = lsode_densematrix_create(d->n_eqns,d->n_eqns);

    d->y_vars = ASC_NEW_ARRAY(struct var_variable *,d->n_eqns+1);
    d->ydot_vars = ASC_NEW_ARRAY(struct var_variable *, d->n_eqns+1);

    integrator_lsode_setup_diffs(blsys);

  /* this is a lie, but we will keep it.
     We handle any linsol/linsolqr based solver. */
  if (strcmp(slv_solver_name(slv_get_selected_solver(blsys->system)),"QRSlv") != 0) {
    ERROR_REPORTER_NOLINE(ASC_USER_ERROR,"QRSlv must be selected before integration.");
    return 0;
  }

  slv_get_status(l_lsode_blsys->system, &status);

  if (status.struct_singular) {
    ERROR_REPORTER_HERE(ASC_USER_ERROR,"Integration will not be performed. The system is structurally singular.");
    lsodesys.status = lsode_nok;
    return 0;
  }

#if defined(STATIC_LSOD) || defined (DYNAMIC_LSOD)

  /* here we assume integrators.c is in charge of dynamic loading */

  slv_get_parameters(blsys->system,&params);
  lsodesys.partitioned = 1;

  nsamples = integrator_getnsamples(blsys);
  if (nsamples <2) {
    ERROR_REPORTER_HERE(ASC_USER_ERROR,"Integration will not be performed. The system has no end sample time defined.");
    lsodesys.status = lsode_nok;
    return 0;
  }
  neq = blsys->n_y;
  nobs = blsys->n_obs;

  x[0] = integrator_get_t(blsys);
  x[1] = x[0]-1; /* make sure we don't start with wierd x[1] */
  lrw = 22 + 9*neq + neq*neq;
  rwork = ASC_NEW_ARRAY_CLEAR(double, lrw+1);
  liw = 20 + neq;
  iwork = ASC_NEW_ARRAY_CLEAR(int, liw+1);
  y = integrator_get_y(blsys, NULL);
  reltol = lsode_get_rtol(blsys);
  abtol = lsode_get_atol(blsys);
  obs = integrator_get_observations(blsys, NULL);
  dydx = ASC_NEW_ARRAY_CLEAR(double, neq+1);
  if (!y || !obs || !abtol || !reltol || !rwork || !iwork || !dydx) {
    lsode_free_mem(y,reltol,abtol,rwork,iwork,obs,dydx);
    ERROR_REPORTER_HERE(ASC_PROG_ERR,"Insufficient memory for lsode.");
    lsodesys.status = lsode_nok;
    return 0;
  }

  /*
    Prepare args and call lsode.
  */
  itol = 4;
  itask = 1;
  istate = 1;
  iopt = 1;
  rwork[4] = integrator_get_stepzero(blsys);
  rwork[5] = integrator_get_maxstep(blsys);
  rwork[6] = integrator_get_minstep(blsys);
  iwork[5] = integrator_get_maxsubsteps(blsys);
  mf = 21;      /* 21 = BDF with exact jacobian. 22 = BDF with finite diff Jacobian */

  /* put the values from derivative system into the record */
  integrator_setsample(blsys, start_index, x[0]);

  integrator_output_init(blsys);

  my_neq = (int)neq;

  /*
    First time entering lsode, x is input. After that,
    lsode uses x as output (y output is y(x)). To drive
    the loop ahead in time, all we need to do is keep upping
    xend.
  */
  blsys->currentstep = 0;
  for (index = start_index; index < finish_index; index++,  blsys->currentstep++) {
    xend = integrator_getsample(blsys, index+1);
    xprev = x[0];
    /* CONSOLE_DEBUG("BEFORE %lu LSODE CALL\n", index); */

# ifndef NO_SIGNAL_TRAPS
    if (setjmp(g_fpe_env)==0) {
# endif /* NO_SIGNAL_TRAPS */

      /* CONSOLE_DEBUG("Calling LSODE with end-time = %f",xend); */
      /*
      switch(mf){
        case 10:
            CONSOLE_DEBUG("Non-stiff (Adams) method; no Jacobian will be used"); break;
        case 21:
            CONSOLE_DEBUG("Stiff (BDF) method, user-supplied full Jacobian"); break;
        case 22:
            CONSOLE_DEBUG("Stiff (BDF) method, internally generated full Jacobian"); break;
        case 24:
            CONSOLE_DEBUG("Stiff (BDF) method, user-supplied banded jacobian"); break;
        case 25:
            CONSOLE_DEBUG("Stiff (BDF) method, internally generated banded jacobian"); break;
        default:
            ERROR_REPORTER_HERE(ASC_PROG_ERR,"Invalid method id %d for LSODE",mf);
            return 0; * failure *
      }
      */

      LSODE(&(LSODE_FEX), &my_neq, y, x, &xend,
            &itol, reltol, abtol, &itask, &istate,
            &iopt ,rwork, &lrw, iwork, &liw, &(LSODE_JEX), &mf);


# ifndef NO_SIGNAL_TRAPS
    } else {
      FPRINTF(stderr,
       "Integration terminated due to float error in LSODE call.\n");
      lsode_free_mem(y,reltol,abtol,rwork,iwork,obs,dydx);
      lsodesys.status = lsode_ok;       /* clean up before we go */
      lsodesys.lastcall = lsode_none;
      if (y_out!=NULL) {
        fclose(y_out);
      }
      if (obs_out!=NULL) {
        fclose(obs_out);
      }
      return 0;
    }
# endif /* NO_SIGNAL_TRAPS */

    /* CONSOLE_DEBUG("AFTER %lu LSODE CALL\n", index); */
    /* this check is better done in fex,jex, but lsode takes no status */
    if (Solv_C_CheckHalt()) {
      if (istate >= 0) {
        istate=-7;
      }
    }

    if (istate < 0 ) {
      /* some kind of error occurred... */
      ERROR_REPORTER_START_HERE(ASC_PROG_ERR);
      lsode_write_istate(istate);
      FPRINTF(ASCERR, "\nFurthest point reached was t = %g.\n",x[0]);
      error_reporter_end_flush();

      lsode_free_mem(y,reltol,abtol,rwork,iwork,obs,dydx);
      integrator_output_close(blsys);
      return 0;
    }

    if (lsodesys.status==lsode_nok) {
      ERROR_REPORTER_HERE(ASC_PROG_ERR,"Integration terminated due to an error in derivative computations.");
      lsode_free_mem(y,reltol,abtol,rwork,iwork,obs,dydx);
      lsodesys.status = lsode_ok;       /* clean up before we go */
      lsodesys.lastcall = lsode_none;
      integrator_output_close(blsys);
      return 0;
    }

    integrator_setsample(blsys, index+1, x[0]);
    /* record when lsode actually came back */
    integrator_set_t(blsys, x[0]);
    integrator_set_y(blsys, y);
    /* put x,y in d in case lsode got x,y by interpolation, as it does  */

    reporterstatus = integrator_output_write(blsys);

    if(reporterstatus==0){
        ERROR_REPORTER_HERE(ASC_USER_ERROR,"Integration cancelled");
        lsode_free_mem(y,reltol,abtol,rwork,iwork,obs,dydx);
        lsodesys.status = lsode_ok;
        lsodesys.lastcall = lsode_none;
        integrator_output_close(blsys);
        return 0;
    }

    if (nobs > 0) {
# ifndef NO_SIGNAL_TRAPS
      if (setjmp(g_fpe_env)==0) {
# endif /* NO_SIGNAL_TRAPS */

        /* solve for obs since d isn't necessarily already
           computed there though lsode's x and y may be.
           Note that since lsode usually steps beyond xend
           x1 usually wouldn't be x0 precisely if the x1/x0
           scheme worked, which it doesn't anyway. */

        LSODE_FEX(&my_neq, x, y, dydx);

        /* calculate observations, if any, at returned x and y. */
        obs = integrator_get_observations(blsys, obs);

        integrator_output_write_obs(blsys);

# ifndef NO_SIGNAL_TRAPS
      } else {
        ERROR_REPORTER_HERE(ASC_PROG_ERR,"Integration terminated due to float error in LSODE FEX call.");
        lsode_free_mem(y,reltol,abtol,rwork,iwork,obs,dydx);
        lsodesys.status = lsode_ok;               /* clean up before we go */
        lsodesys.lastcall = lsode_none;
        integrator_output_close(blsys);
        return 0;
      }
# endif /* NO_SIGNAL_TRAPS */
    }
    /* CONSOLE_DEBUG("Integration completed from %3g to %3g.",xprev,x[0]); */
  }

  CONSOLE_DEBUG("...");
  CONSOLE_DEBUG("Number of steps taken: %1d.", iwork[10]);
  CONSOLE_DEBUG("Number of function evaluations: %1d.", iwork[11]);
  CONSOLE_DEBUG("Number of Jacobian evaluations: %1d.", iwork[12]);
  CONSOLE_DEBUG("...");


  lsode_free_mem(y,reltol,abtol,rwork,iwork,obs,dydx);

  /*
   * return the system to its original state.
   */

  lsodesys.status = lsode_ok;
  lsodesys.lastcall = lsode_none;

  integrator_output_close(blsys);

  CONSOLE_DEBUG("--- LSODE done ---");
  return 1;

#else /* STATIC_LSOD || DYNAMIC_LSOD */

  ERROR_REPORTER_HERE(ASC_PROG_ERR,"Integration will not be performed. LSODE binary not available.");
  lsodesys.status = lsode_nok;
  return 0;

#endif
}

/**
    Function XASCWV is an error reporting function replacing the XERRWV
    routine in lsode.f. The call signature is the same with the original Fortran
    function.

    @see the comments for 'xerrwv' from lsode.f, with which XASCWV is compatible...

    @param msg    = the message (hollerith literal or integer array).
    @param nmes   = the length of msg (number of characters).
    @param nerr   = the error number (not used).
    @param level  = the error level..
            0 or 1 means recoverable (control returns to caller).
            2 means fatal (run is aborted--see note below).
    @param ni     = number of integers (0, 1, or 2) to be printed with message.
    @param i1,i2  = integers to be printed, depending on ni.
    @param nr     = number of reals (0, 1, or 2) to be printed with message.
    @param r1,r2  = reals to be printed, depending on nr.
*/
void XASCWV( char *msg, /* pointer to start of message */
             int *nmes, /* the length of msg (number of characters) */
             int *nerr, /* the error number (not used). */
             int *level,
             int *ni,
             int *i1,
             int *i2,
             int *nr,
             double *r1,
             double *r2
){
    switch(*nerr){
        case 204:
            if(*nr==0)return;
            ERROR_REPORTER_HERE(ASC_PROG_ERR,"Error test failed repeatedly or with abs(h)=hmin.\nt=%f and step size h=%f",*r1,*r2);
            break;
        case 205:
            if(*nr==0)return;
            ERROR_REPORTER_HERE(ASC_PROG_ERR,"Corrector convergence test failed repeatedly or with abs(h)=hmin.\nt=%f and step size h=%f",*r1,*r2);
            break;

        default:
            ERROR_REPORTER_START_NOLINE(ASC_PROG_ERR);

            /* note that %.*s means that a string length (integer) and string pointer are being required */
            FPRINTF(stderr,"LSODE error: %.*s",*nmes,msg);
            if (*ni == 1) {
            FPRINTF(stderr,"\nwhere i1 = %d\n",*i1);
            }
            if (*ni == 2) {
            FPRINTF(stderr,"\nwhere i1 = %d, i2 = %d",*i1,*i2);
            }
            if (*nr == 1) {
            FPRINTF(stderr,"\nwhere r1 = %.13g", *r1);
            }
            if (*nr == 2) {
            FPRINTF(stderr,"\nwhere r1 = %.13g, r2 = %.13g", *r1,*r2);
            }
            error_reporter_end_flush();
    }

    if (*level != 2) {
        return;
    }

    /* NOT reached. lsode does NOT make level 2 calls in our version. */
    error_reporter_end_flush();
    Asc_Panic(3,"xascwv", "LSODE really really confused");
}