vlist.c

#if defined (HAVE_CONFIG_H)
#  include "config.h"
#endif

#include "dmemory.h"
#include "cdi.h"
#include "stream_int.h"
#include "vlist.h"
#include "varscan.h"
#include "namespace.h"
#include "pio_util.h"
#include "resource_handle.h"
#include "vlist_var.h"
#include "vlist_att.h"
#include "pio_rpc.h"

static int VLIST_Debug = 0;

static void vlist_initialize(void);

#if  defined  (HAVE_LIBPTHREAD)
#  include <pthread.h>

static pthread_once_t  _vlist_init_thread = PTHREAD_ONCE_INIT;

#  define VLIST_INIT()        \
  pthread_once(&_vlist_init_thread, vlist_initialize)

#else

static int vlistIsInitialized = 0;

#  define VLIST_INIT()               \
  if ( _vlist_init == FALSE ) vlist_initialize()
#endif


/* FIXME: implementation incomplete, fix once leaf nodes are complete */
static int
vlist_compare(vlist_t *a, vlist_t *b)
{
  int diff;
  diff = (a->nvars != b->nvars) || (a->ngrids != b->ngrids)
    || (a->nzaxis != b->nzaxis) || (a->instID != b->instID)
    || (a->modelID != b->modelID) || (a->tableID != b->tableID)
    || (a->ntsteps != b->ntsteps);
  return diff;
}

static void
vlistPrintKernel(vlist_t *vlistptr, FILE * fp );
static void
vlist_delete(vlist_t *vlistptr);

#ifdef USE_MPI
static int  vlistGetSizeP ( void * vlistptr, MPI_Comm comm );
static void vlistPackP    ( void * vlistptr, void * buff, int size,
                            int *position, MPI_Comm comm );
static int  vlistTxCode   ( void );
#endif

resOps vlist_ops = {
  (valCompareFunc)vlist_compare,
  (valDestroyFunc)vlist_delete,
  (valPrintFunc)vlistPrintKernel
#ifdef USE_MPI
  , vlistGetSizeP,
  vlistPackP,
  vlistTxCode
#endif
};


vlist_t *vlist_to_pointer(int code)
{
  VLIST_INIT();
  return reshGetVal(code, &vlist_ops );
}

static
void vlist_init_entry(vlist_t *vlistptr)
{
  vlistptr->self           = reshPut(vlistptr, &vlist_ops);

  vlistptr->nvars          = 0;
  vlistptr->vars           = NULL;
  vlistptr->ngrids         = 0;
  vlistptr->nzaxis         = 0;
  vlistptr->taxisID        = CDI_UNDEFID;
  vlistptr->instID         = cdiDefaultInstID;
  vlistptr->modelID        = cdiDefaultModelID;
  vlistptr->tableID        = cdiDefaultTableID;
  vlistptr->varsAllocated  = 0;
  vlistptr->ntsteps        = CDI_UNDEFID;
  vlistptr->atts.nalloc    = MAX_ATTRIBUTES;
  vlistptr->atts.nelems    = 0;
}

static
vlist_t *vlist_new_entry(void)
{
  vlist_t *vlistptr;

  vlistptr = (vlist_t *)xmalloc(sizeof(vlist_t));

  vlist_init_entry(vlistptr);

  return (vlistptr);
}

static
void vlist_delete_entry(vlist_t *vlistptr)
{
  int idx;

  idx = vlistptr->self;

  reshRemove(idx, &vlist_ops );

  free(vlistptr);

  if ( VLIST_Debug )
    Message("Removed idx %d from vlist list", idx);
}

static
void vlist_initialize(void)
{
  char *env;

  env = getenv("VLIST_DEBUG");
  if ( env ) VLIST_Debug = atoi(env);
}

static
void vlist_copy(vlist_t *vlistptr2, vlist_t *vlistptr1)
{
  int vlistID2;

  vlistID2 = vlistptr2->self;
  memcpy(vlistptr2, vlistptr1, sizeof(vlist_t));
  vlistptr2->atts.nelems = 0;
  vlistptr2->self = vlistID2;
}

static
void vlist_check_ptr(const char *caller, vlist_t *vlistptr)
{
  if ( vlistptr == NULL )
    Errorc("vlist undefined!");
}

/*
@Function  vlistCreate
@Title     Create a variable list

@Prototype int vlistCreate(void)

@Example
Here is an example using @func{vlistCreate} to create a variable list
and add a variable with @func{vlistDefVar}.

@Source
#include "cdi.h"
   ...
int vlistID, varID;
   ...
vlistID = vlistCreate();
varID = vlistDefVar(vlistID, gridID, zaxisID, TSTEP_INSTANT);
   ...
streamDefVlist(streamID, vlistID);
   ...
vlistDestroy(vlistID);
   ...
@EndSource
@EndFunction
*/
int vlistCreate(void)
{
  int vlistID = 0;
  vlist_t *vlistptr;

  VLIST_INIT();

  vlistptr = vlist_new_entry();

  vlistID = vlistptr->self;

  return (vlistID);
}

static void
vlist_delete(vlist_t *vlistptr)
{
  vlist_check_ptr(__func__, vlistptr);

  int vlistID = vlistptr->self;

  vlistDelAtts(vlistID, CDI_GLOBAL);

  int nvars = vlistptr->nvars;

  for (int varID = 0; varID < nvars; varID++ )
    {
      if ( vlistptr->vars[varID].levinfo )  free(vlistptr->vars[varID].levinfo);
      if ( vlistptr->vars[varID].name )     free(vlistptr->vars[varID].name);
      if ( vlistptr->vars[varID].longname ) free(vlistptr->vars[varID].longname);
      if ( vlistptr->vars[varID].stdname )  free(vlistptr->vars[varID].stdname);
      if ( vlistptr->vars[varID].units )    free(vlistptr->vars[varID].units);

      if ( vlistptr->vars[varID].ensdata )  free(vlistptr->vars[varID].ensdata);
      if ( vlistptr->vars[varID].deco )     free(vlistptr->vars[varID].deco);
      vlistDelAtts(vlistID, varID);
    }

  if ( vlistptr->vars ) free(vlistptr->vars);

  vlist_delete_entry(vlistptr);
}


/*
@Function  vlistDestroy
@Title     Destroy a variable list

@Prototype void vlistDestroy(int vlistID)
@Parameter
    @Item  vlistID  Variable list ID, from a previous call to @fref{vlistCreate}

@EndFunction
*/
void vlistDestroy(int vlistID)
{
  vlist_t *vlistptr;

  vlistptr = vlist_to_pointer(vlistID);

  vlist_delete(vlistptr);
}

/*
@Function  vlistCopy
@Title     Copy a variable list

@Prototype void vlistCopy(int vlistID2, int vlistID1)
@Parameter
    @Item  vlistID2  Target variable list ID
    @Item  vlistID1  Source variable list ID

@Description
The function @func{vlistCopy} copies all entries from vlistID1 to vlistID2.

@EndFunction
*/
void vlistCopy(int vlistID2, int vlistID1)
{
  vlist_t *vlistptr1, *vlistptr2;

  vlistptr1 = vlist_to_pointer(vlistID1);
  vlistptr2 = vlist_to_pointer(vlistID2);

  vlist_check_ptr(__func__, vlistptr1);
  vlist_check_ptr(__func__, vlistptr2);

  vlist_copy(vlistptr2, vlistptr1);

  vlistCopyVarAtts(vlistID1, CDI_GLOBAL, vlistID2, CDI_GLOBAL);

  if ( vlistptr1->vars )
    {
      int nvars = vlistptr1->nvars;
      int nlevs, varID;

      //vlistptr2->varsAllocated = nvars;
      vlistptr2->vars = (var_t *) malloc(vlistptr2->varsAllocated*sizeof(var_t));
      memcpy(vlistptr2->vars, vlistptr1->vars, vlistptr2->varsAllocated*sizeof(var_t));

      for ( varID = 0; varID < nvars; varID++ )
        {
          if ( vlistptr1->vars[varID].name )
            vlistptr2->vars[varID].name = strdupx(vlistptr1->vars[varID].name);

          if ( vlistptr1->vars[varID].longname )
            vlistptr2->vars[varID].longname = strdupx(vlistptr1->vars[varID].longname);

          if ( vlistptr1->vars[varID].stdname )
            vlistptr2->vars[varID].stdname = strdupx(vlistptr1->vars[varID].stdname);

          if ( vlistptr1->vars[varID].units )
            vlistptr2->vars[varID].units = strdupx(vlistptr1->vars[varID].units);

          nlevs = vlistptr1->vars[varID].nlevs;
          vlistptr2->vars[varID].levinfo = (levinfo_t *) malloc(nlevs*sizeof(levinfo_t));
          memcpy(vlistptr2->vars[varID].levinfo,
                 vlistptr1->vars[varID].levinfo, nlevs*sizeof(levinfo_t));

          if ( vlistptr2->vars[varID].ensdata ) free(vlistptr2->vars[varID].ensdata);
          if ( vlistptr1->vars[varID].ensdata )
            {
              vlistptr2->vars[varID].ensdata = (ensinfo_t *) malloc(sizeof(ensinfo_t));
              memcpy(vlistptr2->vars[varID].ensdata,
                     vlistptr1->vars[varID].ensdata, sizeof(ensinfo_t));
            }
          if ( vlistptr1->vars[varID].deco )
            {
              size_t decoSize = (size_t)vlistptr1->vars[varID].decoSize;
              vlistptr2->vars[varID].deco = malloc(decoSize * sizeof (deco_t));
              memcpy(vlistptr2->vars[varID].deco, vlistptr1->vars[varID].deco,
                     decoSize * sizeof (deco_t));
            }

	  vlistptr2->vars[varID].atts.nelems = 0;
	  vlistCopyVarAtts(vlistID1, varID, vlistID2, varID);
	}
    }
}

/*
@Function  vlistDuplicate
@Title     Duplicate a variable list

@Prototype int vlistDuplicate(int vlistID)
@Parameter
    @Item  vlistID  Variable list ID, from a previous call to @fref{vlistCreate}

@Description
The function @func{vlistDuplicate} duplicates the variable list from vlistID1.

@Result
@func{vlistDuplicate} returns an identifier to the duplicated variable list.

@EndFunction
*/
int vlistDuplicate(int vlistID)
{
  int vlistIDnew;
  vlist_t *vlistptr;

  vlistptr = vlist_to_pointer(vlistID);

  vlist_check_ptr(__func__, vlistptr);

  vlistIDnew = vlistCreate();

  vlistCopy(vlistIDnew, vlistID);

  if ( ! namespaceHasLocalFile ( namespaceGetActive ()))
    reshSetStatus ( vlistIDnew, &vlist_ops, SUSPENDED );

  return (vlistIDnew);
}


void vlistClearFlag(int vlistID)
{
  int varID, levID;
  vlist_t *vlistptr;

  vlistptr = vlist_to_pointer(vlistID);

  for ( varID = 0; varID < vlistptr->nvars; varID++ )
    {
      vlistptr->vars[varID].flag = FALSE;
      for ( levID = 0; levID < vlistptr->vars[varID].nlevs; levID++ )
        {
          vlistptr->vars[varID].levinfo[levID].flag = FALSE;
        }
    }
}


int vlistInqZaxis(int vlistID, int zaxistype, int nlevels, double *levels, int lbounds, double *levels2,
                  int vctsize, const double *vct)
{
  int zaxisdefined;
  int nzaxis;
  int zaxisID = CDI_UNDEFID;
  int index;
  int zaxisglobdefined = 0;
  vlist_t *vlistptr;

  vlistptr = vlist_to_pointer(vlistID);

  vlist_check_ptr(__func__, vlistptr);

  zaxisdefined = 0;
  nzaxis = vlistptr->nzaxis;

  for ( index = 0; index < nzaxis; index++ )
    {
      zaxisID = vlistptr->zaxisIDs[index];

      if ( zaxisCompare(zaxisID, zaxistype, nlevels, lbounds, levels, NULL, NULL, 0) == 0 )
        {
          zaxisdefined = 1;
          break;
        }
    }

  if ( ! zaxisdefined )
    {
      nzaxis = zaxisSize();
      for ( zaxisID = 0; zaxisID < nzaxis; zaxisID++ )
        if ( zaxisCompare(zaxisID, zaxistype, nlevels, lbounds, levels, NULL, NULL, 0) == 0 )
          {
            zaxisglobdefined = 1;
            break;
          }
    }

  if ( ! zaxisdefined )
    {
      if ( ! zaxisglobdefined )
	{
	  zaxisID = zaxisCreate(zaxistype, nlevels);
	  zaxisDefLevels(zaxisID, levels);
	  if ( lbounds )
	    {
	      zaxisDefLbounds(zaxisID, levels);
	      zaxisDefUbounds(zaxisID, levels2);
	    }

	  if ( zaxistype == ZAXIS_HYBRID )
	    {
	      if ( vctsize > 0 )
		zaxisDefVct(zaxisID, vctsize, vct);
	      else
		Warning("VCT missing");
	    }
	}

      nzaxis = vlistptr->nzaxis;
      vlistptr->zaxisIDs[nzaxis] = zaxisID;
      vlistptr->nzaxis++;
    }

  return (zaxisID);
}

/*
@Function  vlistCopyFlag
@Title     Copy some entries of a variable list

@Prototype void vlistCopyFlag(int vlistID2, int vlistID1)
@Parameter
    @Item  vlistID2  Target variable list ID
    @Item  vlistID1  Source variable list ID

@Description
The function @func{vlistCopyFlag} copies all entries with a flag from vlistID1 to vlistID2.

@EndFunction
*/
void vlistCopyFlag(int vlistID2, int vlistID1)
{
  vlist_t *vlistptr1, *vlistptr2;

  vlistptr1 = vlist_to_pointer(vlistID1);
  vlistptr2 = vlist_to_pointer(vlistID2);

  vlist_check_ptr(__func__, vlistptr1);
  vlist_check_ptr(__func__, vlistptr2);

  vlist_copy(vlistptr2, vlistptr1);

  vlistCopyVarAtts(vlistID1, CDI_GLOBAL, vlistID2, CDI_GLOBAL);

  if ( vlistptr1->vars )
    {
      int nvars = vlistptr1->nvars;
      int nvars2 = 0, levID2;
      int nlevs, nlevs2, levID, varID, varID2;
      int gridID, zaxisID;
      int index;

      vlistptr2->ngrids = 0;
      vlistptr2->nzaxis = 0;

      for ( varID = 0; varID < nvars; varID++ )
        if ( vlistptr1->vars[varID].flag ) nvars2++;

      vlistptr2->nvars = nvars2;
      vlistptr2->varsAllocated = nvars2;
      if ( nvars2 > 0 )
        vlistptr2->vars  = (var_t *) malloc(nvars2*sizeof(var_t));
      else
        vlistptr2->vars  = NULL;

      varID2 = 0;
      for ( varID = 0; varID < nvars; varID++ )
	if ( vlistptr1->vars[varID].flag )
	  {
	    vlistptr2->vars[varID2].flag = FALSE;
	    zaxisID = vlistptr1->vars[varID].zaxisID;
	    gridID  = vlistptr1->vars[varID].gridID;

	    memcpy(&vlistptr2->vars[varID2], &vlistptr1->vars[varID], sizeof(var_t));

	    vlistptr1->vars[varID].fvarID = varID2;
	    vlistptr2->vars[varID2].fvarID = varID;

	    vlistptr2->vars[varID2].mvarID = varID2;

	    if ( vlistptr1->vars[varID].name )
	      vlistptr2->vars[varID2].name = strdupx(vlistptr1->vars[varID].name);

	    if ( vlistptr1->vars[varID].longname )
	      vlistptr2->vars[varID2].longname = strdupx(vlistptr1->vars[varID].longname);

	    if ( vlistptr1->vars[varID].stdname )
	      vlistptr2->vars[varID2].stdname = strdupx(vlistptr1->vars[varID].stdname);

	    if ( vlistptr1->vars[varID].units )
	      vlistptr2->vars[varID2].units = strdupx(vlistptr1->vars[varID].units);

	    nlevs  = vlistptr1->vars[varID].nlevs;
	    nlevs2 = 0;
	    for ( levID = 0; levID < nlevs; levID++ )
	      if ( vlistptr1->vars[varID].levinfo[levID].flag ) nlevs2++;

	    vlistptr2->vars[varID2].levinfo = (levinfo_t *) malloc(nlevs2*sizeof(levinfo_t));

	    vlistptr2->vars[varID2].atts.nelems = 0;
	    vlistCopyVarAtts(vlistID1, varID, vlistID2, varID2);

	    if ( nlevs != nlevs2 )
	      {
		int zaxisType;
		int zaxisID2;
		int nvct = 0;
		int lbounds;
		double *levels;
		double *levels2;
		const double *vct = NULL;

		zaxisID = vlistptr1->vars[varID].zaxisID;
		levels = (double *) malloc(nlevs2*sizeof(double));
		levID2 = 0;
		for ( levID = 0; levID < nlevs; levID++ )
		  if ( vlistptr1->vars[varID].levinfo[levID].flag )
		    {
		      vlistptr1->vars[varID].levinfo[levID].flevelID = levID2;
		      vlistptr1->vars[varID].levinfo[levID].mlevelID = levID2;
		      levels[levID2++] = zaxisInqLevel(zaxisID, levID);
		    }

		zaxisType = zaxisInqType(zaxisID);

		if ( zaxisType == ZAXIS_HYBRID )
		  {
		    nvct = zaxisInqVctSize(zaxisID);
		    vct  = zaxisInqVctPtr(zaxisID);
		  }
		lbounds  = 0;     /* <------------ have to defined */
		levels2  = NULL;  /* <------------ have to defined */
		zaxisID2 = vlistInqZaxis(vlistID2, zaxisType, nlevs2, levels, lbounds, levels2, nvct, vct);
		free(levels);

		{
		  char ctemp[256];
		  zaxisInqName(zaxisID, ctemp);
		  zaxisDefName(zaxisID2, ctemp);
		  zaxisInqLongname(zaxisID, ctemp);
		  zaxisDefLongname(zaxisID2, ctemp);
		  zaxisInqUnits(zaxisID, ctemp);
		  zaxisDefUnits(zaxisID2, ctemp);
		}

		zaxisID = zaxisID2;
		vlistptr2->vars[varID2].zaxisID = zaxisID2;
		vlistptr2->vars[varID2].nlevs   = nlevs2;
	      }

	    for ( levID = 0; levID < nlevs2; levID++ )
	      {
		vlistptr2->vars[varID2].levinfo[levID].flag  = FALSE;
		vlistptr2->vars[varID2].levinfo[levID].index = -1;
	      }

	    levID2 = 0;
	    for ( levID = 0; levID < nlevs; levID++ )
	      if ( vlistptr1->vars[varID].levinfo[levID].flag )
		{
		  vlistptr2->vars[varID2].levinfo[levID2].flevelID = levID;
		  vlistptr2->vars[varID2].levinfo[levID2].mlevelID = levID;
		  levID2++;
		}

	    for ( index = 0; index <vlistptr2->ngrids; index++ )
	      if (vlistptr2->gridIDs[index] == gridID ) break;

	    if ( index == vlistptr2->ngrids )
	      {
		vlistptr2->gridIDs[vlistptr2->ngrids++] = gridID;
		if (vlistptr2->ngrids >= MAX_GRIDS_PS )
		  Error("Internal Problem! More than %d grids.", MAX_GRIDS_PS);
	      }

	    for ( index = 0; index < vlistptr2->nzaxis; index++ )
	      if ( vlistptr2->zaxisIDs[index] == zaxisID ) break;

	    if ( index == vlistptr2->nzaxis )
	      {
		vlistptr2->zaxisIDs[vlistptr2->nzaxis++] = zaxisID;
		if (vlistptr2->nzaxis >= MAX_ZAXES_PS )
		  Error("Internal Problem! More than %d zaxis.", MAX_ZAXES_PS);
	      }

	    varID2++;
	  }
    }
}

/*
@Function  vlistCat
@Title     Concatenate two variable lists

@Prototype void vlistCat(int vlistID2, int vlistID1)
@Parameter
    @Item  vlistID2  Target variable list ID
    @Item  vlistID1  Source variable list ID

@Description
Concatenate the variable list vlistID1 at the end of vlistID2.

@EndFunction
*/
void vlistCat(int vlistID2, int vlistID1)
{
  int nvars, nvars1, nvars2;
  int varID, varID2, nlevs;
  int index, gridID, zaxisID;
  vlist_t *vlistptr1, *vlistptr2;

  vlistptr1 = vlist_to_pointer(vlistID1);
  vlistptr2 = vlist_to_pointer(vlistID2);

  vlist_check_ptr(__func__, vlistptr1);
  vlist_check_ptr(__func__, vlistptr2);

  nvars1 = vlistptr1->nvars;
  nvars2 = vlistptr2->nvars;
  nvars = nvars1 + nvars2;
  vlistptr2->nvars = nvars;

  if ( nvars > vlistptr2->varsAllocated )
    {
      vlistptr2->varsAllocated = nvars;
      vlistptr2->vars = (var_t *) realloc(vlistptr2->vars, nvars*sizeof(var_t));
    }
  memcpy(vlistptr2->vars+nvars2, vlistptr1->vars, nvars1*sizeof(var_t));

  for ( varID = 0; varID < nvars1; varID++ )
    {
      varID2 = varID + nvars2;
      vlistptr1->vars[varID].fvarID = varID2;
      vlistptr2->vars[varID2].fvarID = varID;

      vlistptr1->vars[varID].mvarID = varID2;
      vlistptr2->vars[varID2].mvarID = varID;

      if ( vlistptr1->vars[varID].param < 0 )
	{
	  int pnum, pcat, pdis;
	  cdiDecodeParam(vlistptr1->vars[varID].param, &pnum, &pcat, &pdis);
	  pnum=-(varID2+1);
	  vlistptr2->vars[varID2].param = cdiEncodeParam(pnum, pcat, pdis);
	}

      if ( vlistptr1->vars[varID].name )
        vlistptr2->vars[varID2].name = strdupx(vlistptr1->vars[varID].name);

      if ( vlistptr1->vars[varID].longname )
        vlistptr2->vars[varID2].longname = strdupx(vlistptr1->vars[varID].longname);

      if ( vlistptr1->vars[varID].stdname )
        vlistptr2->vars[varID2].stdname = strdupx(vlistptr1->vars[varID].stdname);

      if ( vlistptr1->vars[varID].units )
        vlistptr2->vars[varID2].units = strdupx(vlistptr1->vars[varID].units);

      nlevs = vlistptr1->vars[varID].nlevs;
      vlistptr2->vars[varID2].levinfo = (levinfo_t *) malloc(nlevs*sizeof(levinfo_t));
      memcpy(vlistptr2->vars[varID2].levinfo, vlistptr1->vars[varID].levinfo, nlevs*sizeof(levinfo_t));

      if ( vlistptr1->vars[varID].ensdata )
        {
          vlistptr2->vars[varID2].ensdata = (ensinfo_t *) malloc(sizeof(ensinfo_t));
          memcpy(vlistptr2->vars[varID2].ensdata, vlistptr1->vars[varID].ensdata, sizeof(ensinfo_t));
        }

      vlistptr2->vars[varID2].atts.nelems = 0;
      vlistCopyVarAtts(vlistID1, varID, vlistID2, varID2);

      gridID = vlistptr1->vars[varID].gridID;
      for ( index = 0; index < vlistptr2->ngrids; index++ )
        if ( gridID == vlistptr2->gridIDs[index] ) break;

      if ( index == vlistptr2->ngrids )
	{
	  vlistptr2->gridIDs[vlistptr2->ngrids++] = gridID;
	  if ( vlistptr2->ngrids >= MAX_GRIDS_PS )
	    Error("Internal Problem! More than %d grids.", MAX_GRIDS_PS);
	}

      zaxisID = vlistptr1->vars[varID].zaxisID;
      for ( index = 0; index < vlistptr2->nzaxis; index++ )
        if ( zaxisID == vlistptr2->zaxisIDs[index] ) break;

      if ( index == vlistptr2->nzaxis )
	{
	  vlistptr2->zaxisIDs[vlistptr2->nzaxis++] = zaxisID;
	  if ( vlistptr2->nzaxis >= MAX_ZAXES_PS )
	    Error("Internal Problem! More than %d zaxis.", MAX_ZAXES_PS);
	}
    }
}

/*
@Function  vlistMerge
@Title     Merge two variable lists

@Prototype void vlistMerge(int vlistID2, int vlistID1)
@Parameter
    @Item  vlistID2  Target variable list ID
    @Item  vlistID1  Source variable list ID

@Description
Merge the variable list vlistID1 to the variable list vlistID2.

@EndFunction
*/
void vlistMerge(int vlistID2, int vlistID1)
{
  int nvars1, nvars2;
  int varID = 0, varID2, levID, nlevs, nlevs1, nlevs2;
  int index, zaxisID;
  int zaxisID1, zaxisID2;
  int *lvar;
  double *levels;
  vlist_t *vlistptr1, *vlistptr2;

  vlistptr1 = vlist_to_pointer(vlistID1);
  vlistptr2 = vlist_to_pointer(vlistID2);

  vlist_check_ptr(__func__, vlistptr1);
  vlist_check_ptr(__func__, vlistptr2);

  nvars1 = vlistptr1->nvars;
  nvars2 = vlistptr2->nvars;

  if ( nvars1 == nvars2 )
    {
      for ( varID = 0; varID < nvars2; varID++ )
	{
	  if ( vlistptr1->vars[varID].name && vlistptr2->vars[varID].name )
	    {
	      if ( strcmp(vlistptr1->vars[varID].name,
			  vlistptr2->vars[varID].name) != 0 ) break;
	    }
	  else
	    {
	      if ( vlistptr1->vars[varID].param != vlistptr2->vars[varID].param )
		break;
	    }
	}
    }

  if ( varID == nvars2 ) /* same variables in vlistID1 and vlistID2 */
    {
      for ( varID = 0; varID < nvars2; varID++ )
        {
          vlistptr1->vars[varID].fvarID = varID;
          vlistptr2->vars[varID].fvarID = varID;

          vlistptr1->vars[varID].mvarID = varID;
          vlistptr2->vars[varID].mvarID = varID;

          nlevs1 = vlistptr1->vars[varID].nlevs;
          nlevs2 = vlistptr2->vars[varID].nlevs;

          nlevs = nlevs1 + nlevs2;

          vlistptr2->vars[varID].nlevs = nlevs;
          /*
          fprintf(stderr, "var %d %d %d %d %d\n", varID, nlevs1, nlevs2, nlevs, sizeof(levinfo_t));
          */
          vlistptr2->vars[varID].levinfo =
            (levinfo_t *) realloc(vlistptr2->vars[varID].levinfo, nlevs*sizeof(levinfo_t));

	  memcpy(vlistptr2->vars[varID].levinfo+nlevs2,
		 vlistptr1->vars[varID].levinfo, nlevs1*sizeof(levinfo_t));

	  for ( levID = 0; levID < nlevs1; levID++ )
	    {
	      vlistptr1->vars[varID].levinfo[levID].mlevelID = nlevs2 + levID;
	    }
	}

      lvar = (int *) malloc(nvars2*sizeof(int));
      for ( varID = 0; varID < nvars2; varID++ ) lvar[varID] = FALSE;

      for ( varID = 0; varID < nvars2; varID++ )
        {
          if ( lvar[varID] == TRUE ) continue;

          zaxisID1 = vlistptr1->vars[varID].zaxisID;
          zaxisID2 = vlistptr2->vars[varID].zaxisID;
          /*
          nlevs1 = vlistptr1->vars[varID].nlevs;
          nlevs2 = vlistptr2->vars[varID].nlevs;
          */
          nlevs1 = zaxisInqSize(zaxisID1);
          nlevs2 = zaxisInqSize(zaxisID2);
          /*
          fprintf(stderr, "zaxis %d %d %d %d\n", zaxisID1, zaxisID2, nlevs1, nlevs2);
          */
          nlevs = nlevs1 + nlevs2;

          zaxisID = zaxisDuplicate(zaxisID2);

          zaxisResize(zaxisID, nlevs);

          levels = (double *) malloc(nlevs1*sizeof(double));

          zaxisInqLevels(zaxisID1, levels);
          /*
          for ( levID = 0; levID < nlevs1; levID++ )
            fprintf(stderr, "%d %d %d %d %d %g\n", varID, levID, nlevs1, nlevs2, vlistptr2->vars[varID].nlevs, levels[levID]);
          */
          for ( levID = 0; levID < nlevs1; levID++ )
            zaxisDefLevel(zaxisID, nlevs2+levID, levels[levID]);

          free(levels);

          for ( index = 0; index < vlistptr2->nzaxis; index++ )
            if ( vlistptr2->zaxisIDs[index] == zaxisID2 )
              vlistptr2->zaxisIDs[index] = zaxisID;

          for ( varID2 = 0; varID2 < nvars2; varID2++ )
            if ( lvar[varID2] == FALSE && vlistptr2->vars[varID2].zaxisID == zaxisID2 )
              {
                vlistptr2->vars[varID2].zaxisID = zaxisID;
                lvar[varID2] = TRUE;
              }
        }

      free(lvar);
    }
  else
    {
      vlistCat(vlistID2, vlistID1);
    }
}

/*
@Function  vlistNvars
@Title     Number of variables in a variable list

@Prototype int vlistNvars(int vlistID)
@Parameter
    @Item  vlistID  Variable list ID, from a previous call to @fref{vlistCreate}

@Description
The function @func{vlistNvars} returns the number of variables in the variable list vlistID.

@Result
@func{vlistNvars} returns the number of variables in a variable list.

@EndFunction
*/
int vlistNvars(int vlistID)
{
  vlist_t *vlistptr;

  vlistptr = vlist_to_pointer(vlistID);

  vlist_check_ptr(__func__, vlistptr);

  return (vlistptr->nvars);
}


int vlistNrecs(int vlistID)
{
  int varID, nrecs = 0;
  vlist_t *vlistptr;

  vlistptr = vlist_to_pointer(vlistID);

  vlist_check_ptr(__func__, vlistptr);

  for ( varID = 0; varID < vlistptr->nvars; varID++ )
    nrecs +=  vlistptr->vars[varID].nlevs;

  return (nrecs);
}


int vlistNumber(int vlistID)
{
  int varID, number, number2, datatype;
  vlist_t *vlistptr;

  vlistptr = vlist_to_pointer(vlistID);

  vlist_check_ptr(__func__, vlistptr);

  datatype = vlistptr->vars[0].datatype;
  if (  datatype== DATATYPE_CPX32 || datatype == DATATYPE_CPX64 )
    number = CDI_COMP;
  else
    number = CDI_REAL;

  for ( varID = 1; varID < vlistptr->nvars; varID++ )
    {
      datatype = vlistptr->vars[varID].datatype;
      if ( datatype == DATATYPE_CPX32 || datatype == DATATYPE_CPX64 )
        number2 = CDI_COMP;
      else
        number2 = CDI_REAL;

      if ( number2 != number )
        {
          number = CDI_BOTH;
          break;
        }
    }

  return (number);
}

/*
@Function  vlistNgrids
@Title     Number of grids in a variable list

@Prototype int vlistNgrids(int vlistID)
@Parameter
    @Item  vlistID  Variable list ID, from a previous call to @fref{vlistCreate}

@Description
The function @func{vlistNgrids} returns the number of grids in the variable list vlistID.

@Result
@func{vlistNgrids} returns the number of grids in a variable list.

@EndFunction
*/
int vlistNgrids(int vlistID)
{
  vlist_t *vlistptr;

  vlistptr = vlist_to_pointer(vlistID);

  vlist_check_ptr(__func__, vlistptr);

  return (vlistptr->ngrids);
}

/*
@Function  vlistNzaxis
@Title     Number of zaxis in a variable list

@Prototype int vlistNzaxis(int vlistID)
@Parameter
    @Item  vlistID  Variable list ID, from a previous call to @fref{vlistCreate}

@Description
The function @func{vlistNzaxis} returns the number of zaxis in the variable list vlistID.

@Result
@func{vlistNzaxis} returns the number of zaxis in a variable list.

@EndFunction
*/
int vlistNzaxis(int vlistID)
{
  vlist_t *vlistptr;

  vlistptr = vlist_to_pointer(vlistID);

  vlist_check_ptr(__func__, vlistptr);

  return (vlistptr->nzaxis);
}


void vlistDefNtsteps(int vlistID, int nts)
{
  vlist_t *vlistptr;

  vlistptr = vlist_to_pointer(vlistID);

  vlist_check_ptr(__func__, vlistptr);

  if ( reshGetStatus ( vlistID, &vlist_ops ) == CLOSED )
    {
      xwarning("%s", "Operation not executed." );
      return;
    }