#! /bin/sh

     ###################################### 
     ##### Model Transformation Tools #####
    ######################################

###############################################################
## Version control history
###############################################################
## $Id$
## $Log$
## Revision 1.57.2.2  2001/06/05 03:20:40  geraint
## added -ae option to select algebraic equation solution method.
##
## Revision 1.57.2.1  2001/05/04 04:07:24  geraint
## Numerical solution of algebraic equations.
## sys_ae.cc written for unsolved inputs.
## Solution of equations using hybrd from MINPACK (as used by Octave fsolve).
##
## Revision 1.57  2001/04/01 03:38:54  geraint
## Reset row to zero after write to file, ready for subsequent runs.

  args (0) = octave_value (x);
  f = feval ("${sys}_state", args, 1);
  return f(0).${vector_value} ();
#endif
}

inline ColumnVector
mtt_${ode} (ColumnVector &x,
	    ColumnVector &u,
	    const double &t,
	    ColumnVector &par)
mtt_rate (ColumnVector &x,
	  ColumnVector &u,
	  const double &t,
	  ColumnVector &par)
{
#ifdef STANDALONE
  return F${sys}_${ode} (x, u, t, par);
#else
  static octave_value_list args, f;
  args (0) = octave_value (x);
  args (1) = octave_value (u);
  args (2) = octave_value (t);
  args (3) = octave_value (par);
  f = feval ("${sys}_${ode}", args, 1);
  return f(0).${vector_value} ();
#endif
}

inline ColumnVector
mtt_${odeo} (ColumnVector &x,
mtt_output (ColumnVector &x,
	     ColumnVector &u,
	     const double &t,
	     ColumnVector &par)
{
#ifdef STANDALONE
  return F${sys}_${odeo} (x, u, t, par);
#else

    {
      x (i) = x0 (i);
    }

  for (register int j = 0, i = 1; i <= ilast; i++)
    {
      u	= mtt_input (x, y, t, par);
      y	= mtt_${odeo} (x, u, t, par);
      y	= mtt_output (x, u, t, par);
      if (0 == j)
	{
           mtt_write (t, x, y, nrows);
	}
EOF
if [ "$method" = "rk4" ]; then
cat << EOF >> $filename

          t2 = t + ddt;

        ColumnVector
          x1 (x),
          x2 (x),
          x3 (x);

        k1 = ddt * mtt_${ode} (x , u, t , par); x1 += k1 * 0.5;
        k2 = ddt * mtt_${ode} (x1, u, t1, par); x2 += k2 * 0.5;
        k3 = ddt * mtt_${ode} (x2, u, t1, par); x3 += k3;
        k4 = ddt * mtt_${ode} (x3, u, t2, par);
        k1 = ddt * mtt_rate (x , u, t , par); x1 += k1 * 0.5;
        k2 = ddt * mtt_rate (x1, u, t1, par); x2 += k2 * 0.5;
        k3 = ddt * mtt_rate (x2, u, t1, par); x3 += k3;
        k4 = ddt * mtt_rate (x3, u, t2, par);
        dx = (k1 + 2.0 * (k2 + k3) + k4) / (6.0 * ddt);
      }
EOF
else
cat << EOF >> $filename
      dx = mtt_${ode} (x, u, t, par);
      dx = mtt_rate (x, u, t, par);
EOF
fi

if [ "$method" = "implicit" ]; then
cat <<EOF >> $filename

      AA = mtt_smxa (x, u, ddt, par);