/**
* Copyright 2005-2007 ECMWF
*
* Licensed under the GNU Lesser General Public License which
* incorporates the terms and conditions of version 3 of the GNU
* General Public License.
* See LICENSE and gpl-3.0.txt for details.
*/

#include "grib_api_internal.h"
#include <math.h>
/*
   This is used by make_class.pl

   START_CLASS_DEF
   CLASS      = accessor
   SUPER      = grib_accessor_class_data_simple_packing
   IMPLEMENTS = unpack_double
   IMPLEMENTS = pack_double
   IMPLEMENTS = value_count
   IMPLEMENTS = init
   MEMBERS= const char*  GRIBEX_sh_bug_present
   MEMBERS= const char*  ieee_floats
   MEMBERS= const char*  laplacianOperatorIsSet
   MEMBERS= const char*  laplacianOperator
   MEMBERS= const char*  sub_j
   MEMBERS= const char*  sub_k
   MEMBERS= const char*  sub_m
   MEMBERS= const char*  pen_j
   MEMBERS= const char*  pen_k
   MEMBERS= const char*  pen_m
   END_CLASS_DEF

 */


/* START_CLASS_IMP */

/*

Don't edit anything between START_CLASS_IMP and END_CLASS_IMP
Instead edit values between START_CLASS_DEF and END_CLASS_DEF
or edit "accessor.class" and rerun ./make_class.pl

*/

static int pack_double(grib_accessor*, const double* val,size_t *len);
static int unpack_double(grib_accessor*, double* val,size_t *len);
static long value_count(grib_accessor*);
static void init(grib_accessor*,const long, grib_arguments* );
static void init_class(grib_accessor_class*);

typedef struct grib_accessor_data_complex_packing {
    grib_accessor          att;
/* Members defined in gen */
/* Members defined in values */
	int  carg;
	const char* seclen;
	const char* offsetdata;
	const char* offsetsection;
	int dirty;
/* Members defined in data_simple_packing */
	int edition;
	const char*  units_factor;
	const char*  units_bias;
	const char*  changing_precision;
	const char*  number_of_values;
	const char*  bits_per_value;
	const char*  reference_value;
	const char*  binary_scale_factor;
	const char*  decimal_scale_factor;
/* Members defined in data_complex_packing */
	const char*  GRIBEX_sh_bug_present;
	const char*  ieee_floats;
	const char*  laplacianOperatorIsSet;
	const char*  laplacianOperator;
	const char*  sub_j;
	const char*  sub_k;
	const char*  sub_m;
	const char*  pen_j;
	const char*  pen_k;
	const char*  pen_m;
} grib_accessor_data_complex_packing;

extern grib_accessor_class* grib_accessor_class_data_simple_packing;

static grib_accessor_class _grib_accessor_class_data_complex_packing = {
    &grib_accessor_class_data_simple_packing,                      /* super                     */
    "data_complex_packing",                      /* name                      */
    sizeof(grib_accessor_data_complex_packing),  /* size                      */
    0,                           /* inited */
    &init_class,                 /* init_class */
    &init,                       /* init                      */
    0,                  /* post_init                      */
    0,                    /* free mem                       */
    0,                       /* describes himself         */
    0,                /* get length of section     */
    &value_count,                /* get number of values      */
    0,                 /* get number of bytes      */
    0,                /* get offset to bytes           */
    0,            /* get native type               */
    0,                /* get sub_section                */
    0,               /* grib_pack procedures long      */
    0,               /* grib_pack procedures long      */
    0,                  /* grib_pack procedures long      */
    0,                /* grib_unpack procedures long    */
    &pack_double,                /* grib_pack procedures double    */
    &unpack_double,              /* grib_unpack procedures double  */
    0,                /* grib_pack procedures string    */
    0,              /* grib_unpack procedures string  */
    0,                 /* grib_pack procedures bytes     */
    0,               /* grib_unpack procedures bytes   */
    0,            /* pack_expression */
    0,              /* notify_change   */
    0,                /* update_size   */
    0,            /* preferred_size   */
    0,                    /* resize   */
    0,      /* nearest_smaller_value */
    0,                       /* next accessor    */
    0,                    /* compare vs. another accessor   */
    0,     /* unpack only ith value          */
    0,     /* unpack a subarray         */
    0,             		/* clear          */
};


grib_accessor_class* grib_accessor_class_data_complex_packing = &_grib_accessor_class_data_complex_packing;


static void init_class(grib_accessor_class* c)
{
	c->dump	=	(*(c->super))->dump;
	c->next_offset	=	(*(c->super))->next_offset;
	c->byte_count	=	(*(c->super))->byte_count;
	c->byte_offset	=	(*(c->super))->byte_offset;
	c->get_native_type	=	(*(c->super))->get_native_type;
	c->sub_section	=	(*(c->super))->sub_section;
	c->pack_missing	=	(*(c->super))->pack_missing;
	c->is_missing	=	(*(c->super))->is_missing;
	c->pack_long	=	(*(c->super))->pack_long;
	c->unpack_long	=	(*(c->super))->unpack_long;
	c->pack_string	=	(*(c->super))->pack_string;
	c->unpack_string	=	(*(c->super))->unpack_string;
	c->pack_bytes	=	(*(c->super))->pack_bytes;
	c->unpack_bytes	=	(*(c->super))->unpack_bytes;
	c->pack_expression	=	(*(c->super))->pack_expression;
	c->notify_change	=	(*(c->super))->notify_change;
	c->update_size	=	(*(c->super))->update_size;
	c->preferred_size	=	(*(c->super))->preferred_size;
	c->resize	=	(*(c->super))->resize;
	c->nearest_smaller_value	=	(*(c->super))->nearest_smaller_value;
	c->next	=	(*(c->super))->next;
	c->compare	=	(*(c->super))->compare;
	c->unpack_double_element	=	(*(c->super))->unpack_double_element;
	c->unpack_double_subarray	=	(*(c->super))->unpack_double_subarray;
	c->clear	=	(*(c->super))->clear;
}

/* END_CLASS_IMP */

typedef unsigned long (*encode_float_proc)(double);
typedef double        (*decode_float_proc)(unsigned long);

static void init(grib_accessor* a,const long v, grib_arguments* args)
{
  grib_accessor_data_complex_packing *self =(grib_accessor_data_complex_packing*)a;

  self->GRIBEX_sh_bug_present     = grib_arguments_get_name(a->parent->h,args,self->carg++);
  self->ieee_floats               = grib_arguments_get_name(a->parent->h,args,self->carg++);
  self->laplacianOperatorIsSet    = grib_arguments_get_name(a->parent->h,args,self->carg++);
  self->laplacianOperator         = grib_arguments_get_name(a->parent->h,args,self->carg++);
  self->sub_j                     = grib_arguments_get_name(a->parent->h,args,self->carg++);
  self->sub_k                     = grib_arguments_get_name(a->parent->h,args,self->carg++);
  self->sub_m                     = grib_arguments_get_name(a->parent->h,args,self->carg++);
  self->pen_j                     = grib_arguments_get_name(a->parent->h,args,self->carg++);
  self->pen_k                     = grib_arguments_get_name(a->parent->h,args,self->carg++);
  self->pen_m                     = grib_arguments_get_name(a->parent->h,args,self->carg++);

  a->flags |= GRIB_ACCESSOR_FLAG_DATA;
}


static long value_count(grib_accessor* a)
{
  grib_accessor_data_complex_packing *self =(grib_accessor_data_complex_packing*)a;
  int ret = 0;

  long   pen_j= 0;
  long   pen_k= 0;
  long   pen_m= 0;

  if(a->length == 0)
    return 0;

  if((ret = grib_get_long_internal(a->parent->h,self->pen_j,&pen_j)) != GRIB_SUCCESS)                         return ret;
  if((ret = grib_get_long_internal(a->parent->h,self->pen_k,&pen_k)) != GRIB_SUCCESS)                         return ret;
  if((ret = grib_get_long_internal(a->parent->h,self->pen_m,&pen_m)) != GRIB_SUCCESS)                         return ret;

  if (pen_j != pen_k || pen_j!=pen_m ) {
    grib_context_log(a->parent->h->context,GRIB_LOG_ERROR,"pen_j=%ld, pen_k=%ld, pen_m=%ld\n",pen_j,pen_k,pen_m);
  	Assert ((pen_j ==  pen_k) && (pen_j == pen_m));
  }
  return  (pen_j+1)*(pen_j+2);
}


static int  unpack_double(grib_accessor* a, double* val, size_t *len)
{
  grib_accessor_data_complex_packing* self =  (grib_accessor_data_complex_packing*)a;

  size_t i = 0;
  int ret = GRIB_SUCCESS;
  long   hcount = 0;
  long   lcount = 0;
  long   hpos = 0;
  long   lup = 0;
  long   mmax = 0;
  long   n_vals = 0;
  double *scals  = NULL;
  double *pscals=NULL,*pval=NULL;

  double s = 0;
  double d = 0;
  double laplacianOperator = 0;
  unsigned char* buf = NULL;
  unsigned char* hres = NULL;
  unsigned char* lres = NULL;
  unsigned long packed_offset;
  long   lpos = 0;

  long   maxv = 0;
  long   GRIBEX_sh_bug_present =0;
  long ieee_floats  = 0;

  long   offsetdata           = 0;
  long   bits_per_value          = 0;
  double reference_value      = 0;
  long   binary_scale_factor         = 0;
  long   decimal_scale_factor = 0;


  long   sub_j= 0;
  long   sub_k= 0;
  long   sub_m= 0;
  long   pen_j= 0;
  long   pen_k= 0;
  long   pen_m= 0;

  double operat= 0;
  int bytes;

  decode_float_proc decode_float = NULL;

  n_vals = grib_value_count(a);

  if(*len < n_vals){
    *len = n_vals;
    return GRIB_ARRAY_TOO_SMALL;
  }

  if((ret = grib_get_long_internal(a->parent->h,self->offsetdata,&offsetdata))
      != GRIB_SUCCESS)   return ret;
  if((ret = grib_get_long_internal(a->parent->h,self->bits_per_value,&bits_per_value))
      != GRIB_SUCCESS)   return ret;
  if((ret = grib_get_double_internal(a->parent->h,self->reference_value,&reference_value))
      != GRIB_SUCCESS)   return ret;
  if((ret = grib_get_long_internal(a->parent->h,self->binary_scale_factor,&binary_scale_factor))
      != GRIB_SUCCESS)           return ret;

  if((ret = grib_get_long_internal(a->parent->h,self->decimal_scale_factor,&decimal_scale_factor))
      != GRIB_SUCCESS)
    return ret;

  if((ret = grib_get_long_internal(a->parent->h,self->GRIBEX_sh_bug_present,&GRIBEX_sh_bug_present))
      != GRIB_SUCCESS)
    return ret;

  if((ret = grib_get_long_internal(a->parent->h,self->ieee_floats,&ieee_floats)) != GRIB_SUCCESS)
    return ret;

  if((ret = grib_get_double_internal(a->parent->h,self->laplacianOperator,&laplacianOperator))
      != GRIB_SUCCESS)
    return ret;
  if((ret = grib_get_long_internal(a->parent->h,self->sub_j,&sub_j)) != GRIB_SUCCESS)
    return ret;
  if((ret = grib_get_long_internal(a->parent->h,self->sub_k,&sub_k)) != GRIB_SUCCESS)
    return ret;
  if((ret = grib_get_long_internal(a->parent->h,self->sub_m,&sub_m)) != GRIB_SUCCESS)
    return ret;
  if((ret = grib_get_long_internal(a->parent->h,self->pen_j,&pen_j)) != GRIB_SUCCESS)
    return ret;
  if((ret = grib_get_long_internal(a->parent->h,self->pen_k,&pen_k)) != GRIB_SUCCESS)
    return ret;
  if((ret = grib_get_long_internal(a->parent->h,self->pen_m,&pen_m)) != GRIB_SUCCESS)
    return ret;

  self->dirty=0;

  switch (ieee_floats) {
    case 0:
      decode_float=grib_long_to_ibm;
	  bytes=4;
      break;
    case 1:
      decode_float=grib_long_to_ieee;
	  bytes=4;
      break;
    case 2:
      decode_float=grib_long_to_ieee64;
	  bytes=8;
      break;
    default:
      return GRIB_NOT_IMPLEMENTED;
  }
  
  Assert (sub_j == sub_k);
  Assert (sub_j == sub_m);
  Assert (pen_j == pen_k);
  Assert (pen_j == pen_m);

  buf = (unsigned char*)a->parent->h->buffer->data;

  maxv = pen_j+1;

  buf  += grib_byte_offset(a);
  hres = buf;
  lres = buf;

  if (pen_j == sub_j) {
	n_vals = (pen_j+1)*(pen_j+2);
	d = grib_power(-decimal_scale_factor,10) ;
  	grib_ieee_decode_array(a->parent->h->context,buf,n_vals,bytes,val);
	if (d) {
		for (i=0;i<n_vals;i++) val[i]*=d;
	}
	return 0;
  }

  packed_offset = grib_byte_offset(a) +  4*(sub_k+1)*(sub_k+2);

  lpos = 8*(packed_offset-offsetdata);

  s = grib_power(binary_scale_factor,2);
  d = grib_power(-decimal_scale_factor,10) ;

  scals   = (double*)grib_context_malloc(a->parent->h->context,maxv*sizeof(double));
  Assert(scals);

  scals[0] = 0;
  for(i=1;i<maxv;i++){
    operat = pow(i*(i+1),laplacianOperator);
    if(operat !=  0)
      scals[i] = (1.0/operat);
    else{
      grib_context_log(a->parent->h->context,GRIB_LOG_WARNING,
           "COMPLEX_PACKING : problem with operator div by zero at index %d of %d \n",
           i , maxv);
      scals[i] = 0;
    }
  }

  /*
  printf("UNPACKING LAPLACE=%.20f\n",laplacianOperator);

  printf("packed offset=%ld\n",packed_offset);
  for(i=0;i<maxv;i++)
    printf("scals[%d]=%g\n",i,scals[i]);*/

  i=0;

  while(maxv>0)
  {
    lup=mmax;
    if(sub_k>=0)
    {
      for(hcount=0;hcount<sub_k+1;hcount++)
      {
        val[i++] =  decode_float(grib_decode_unsigned_long(hres,&hpos,32))*d;
        val[i++] =  decode_float(grib_decode_unsigned_long(hres,&hpos,32))*d;

        if (GRIBEX_sh_bug_present && hcount==sub_k){
 /*  bug in ecmwf data, last row (K+1)is scaled but should not */
          val[i-2] *= scals[lup];
          val[i-1] *= scals[lup];
        }
        lup++;
      }
      sub_k--;
    }

    pscals=scals+lup;
    pval=val+i;
#if FAST_BIG_ENDIAN
    grib_decode_double_array_complex(lres,
                                     &lpos,bits_per_value,
                                     reference_value,s,pscals,(maxv-hcount)*2,pval);
    i+=(maxv-hcount)*2;
#else
    for(lcount=hcount; lcount < maxv ; lcount++)
    {
      val[i++] =  (double) ((grib_decode_unsigned_long(lres, &lpos,
                   bits_per_value)*s)+reference_value)*scals[lup];
      val[i++] =  (double) ((grib_decode_unsigned_long(lres, &lpos,
                   bits_per_value)*s)+reference_value)*scals[lup];
      lup++;
    }
#endif

    maxv--;
    hcount=0;
    mmax++;
  }

  Assert(*len >= i);
  *len = i;

  if(d != 1) {
    for(i=0;i<*len;i++)
      val[i++] *= d;
  }

  grib_context_free(a->parent->h->context,scals);

  return ret;

}



#define MAXVAL(a,b) a>b?a:b

static double calculate_pfactor(grib_context *ctx,const double* spectralField, long fieldTruncation, long subsetTruncation)
{
  /*long n_vals = ((fieldTruncation+1)*(fieldTruncation+2));*/
  long loop, index, m, n = 0;
  double pFactor, zeps = 1.0e-15;
  long ismin = (subsetTruncation+1), ismax = (fieldTruncation+1);
  double* weights, range, * norms;
  double weightedSumOverX = 0.0, weightedSumOverY = 0.0, sumOfWeights = 0.0, x, y;
  double numerator = 0.0, denominator = 0.0, slope;

  /*
  // Setup the weights
   */

  range = (double) (ismax - ismin +1);

  weights = (double*) grib_context_malloc(ctx,(ismax+1)*sizeof(double));
  for( loop = ismin; loop <= ismax; loop++ )
    weights[loop] = range / (double) (loop-ismin+1);
  /*
  // Compute norms
  // Handle values 2 at a time (real and imaginary parts).
   */
  norms = (double*) grib_context_malloc(ctx,(ismax+1)*sizeof(double));

  for( loop = 0; loop < ismax+1; loop++ ) norms[loop] = 0.0;
  /*
  // Form norms for the rows which contain part of the unscaled subset.
   */

  index = -2;
  for( m = 0; m < subsetTruncation; m++ )
    for( n = m; n <= fieldTruncation; n++ ) {
      index += 2;
      if( n >= subsetTruncation ) {
        norms[n] = MAXVAL(norms[n],fabs(spectralField[index]));
        norms[n] = MAXVAL(norms[n],fabs(spectralField[index+1]));
      }
    }
  /*
  // Form norms for the rows which do not contain part of the unscaled subset.
   */

  for( m = subsetTruncation; m <= fieldTruncation; m++ )
    for( n = m; n <= fieldTruncation; n++ ) {
      index += 2;
      norms[n] = MAXVAL(norms[n],fabs(spectralField[index]));
      norms[n] = MAXVAL(norms[n],fabs(spectralField[index+1]));
    }

  /*
  // Ensure the norms have a value which is not too small in case of
  // problems with math functions (e.g. LOG).
   */

  for( loop = ismin; loop <= ismax; loop++ ) {
    norms[n] = MAXVAL(norms[n],zeps);
    if( norms[n] == zeps ) weights[n] = 100.0 * zeps;
  }

  /*
  // Do linear fit to find the slope
   */

  for( loop = ismin; loop <= ismax; loop++ ) {
    x = log( (double) (loop*(loop+1)) );
    y = log( norms[loop] );
    weightedSumOverX = weightedSumOverX + x * weights[loop];
    weightedSumOverY = weightedSumOverY + y * weights[loop];
    sumOfWeights = sumOfWeights + weights[loop];
  }
  weightedSumOverX = weightedSumOverX / sumOfWeights;
  weightedSumOverY = weightedSumOverY / sumOfWeights;

  /*
  // Perform a least square fit for the equation
   */

  for( loop = ismin; loop <= ismax; loop++ ) {

    x = log( (double)(loop*(loop+1)) );
    y = log( norms[loop] );
    numerator =
      numerator + weights[loop] * (y-weightedSumOverY) * (x-weightedSumOverX);
    denominator =
      denominator + weights[loop] * ((x-weightedSumOverX) * (x-weightedSumOverX));
  }
  slope = numerator / denominator;

  grib_context_free(ctx,weights);
  grib_context_free(ctx,norms);

  pFactor = -slope;
  if( pFactor < -9999.9 ) pFactor = -9999.9;
  if( pFactor > 9999.9 )  pFactor = 9999.9;
  return pFactor;
}


static int pack_double(grib_accessor* a, const double* val, size_t *len) {

  grib_accessor_data_complex_packing* self =  (grib_accessor_data_complex_packing*)a;

  size_t i = 0;
  int ret = GRIB_SUCCESS;
  long   hcount = 0;
  long   lcount = 0;
  long   hpos = 0;
  long   lup = 0;
  long   mmax = 0;
  long   n_vals = 0;
  double *scals  = NULL;

  double s = 0;
  double d = 0;

  unsigned char* buf    = NULL;

  size_t         buflen = 0;

  size_t         hsize = 0;
  size_t         lsize = 0;


  unsigned char* hres = NULL;
  unsigned char* lres = NULL;

  long   lpos = 0;
  long   maxv = 0;

  long   offsetdata           = 0;
  long   bits_per_value          = 0;
  double reference_value      = 0;
  long   binary_scale_factor         = 0;
  long   decimal_scale_factor = 0;
  long   laplacianOperatorIsSet = 0;

  double laplacianOperator = 0;
  long   sub_j= 0;
  long   sub_k= 0;
  long   sub_m= 0;
  long   pen_j= 0;
  long   pen_k= 0;
  long   pen_m= 0;
  long   GRIBEX_sh_bug_present =0;
  long   ieee_floats =0;
  double min = 0;
  double max = 0;
  double current_val = 0;
  short mixmax_unset = 0;
  int bytes;

  encode_float_proc encode_float = NULL;

  if (*len ==0) return GRIB_NO_VALUES;

  if((ret = grib_get_long_internal(a->parent->h,self->offsetdata,&offsetdata)) != GRIB_SUCCESS)
	  return ret;
  if((ret = grib_get_long_internal(a->parent->h,self->bits_per_value,&bits_per_value)) != GRIB_SUCCESS)
	  return ret;

  if((ret = grib_get_long_internal(a->parent->h,self->decimal_scale_factor,&decimal_scale_factor)) != GRIB_SUCCESS)
    return ret;

  if((ret = grib_get_long_internal(a->parent->h,self->GRIBEX_sh_bug_present,&GRIBEX_sh_bug_present)) != GRIB_SUCCESS)
    return ret;

  if((ret = grib_get_long_internal(a->parent->h,self->ieee_floats,&ieee_floats)) != GRIB_SUCCESS)
    return ret;

  if((ret = grib_get_long_internal(a->parent->h,self->laplacianOperatorIsSet,&laplacianOperatorIsSet)) != GRIB_SUCCESS)
	  return ret;
  if((ret = grib_get_double_internal(a->parent->h,self->laplacianOperator,&laplacianOperator)) != GRIB_SUCCESS)
	  return ret;

  if((ret = grib_get_long_internal(a->parent->h,self->sub_j,&sub_j)) != GRIB_SUCCESS)
	  return ret;
  if((ret = grib_get_long_internal(a->parent->h,self->sub_k,&sub_k)) != GRIB_SUCCESS)
	  return ret;
  if((ret = grib_get_long_internal(a->parent->h,self->sub_m,&sub_m)) != GRIB_SUCCESS)
	  return ret;
  if((ret = grib_get_long_internal(a->parent->h,self->pen_j,&pen_j)) != GRIB_SUCCESS)
	  return ret;
  if((ret = grib_get_long_internal(a->parent->h,self->pen_k,&pen_k)) != GRIB_SUCCESS)
	  return ret;
  if((ret = grib_get_long_internal(a->parent->h,self->pen_m,&pen_m)) != GRIB_SUCCESS)
	  return ret;

  self->dirty=1;


  switch (ieee_floats) {
    case 0:
      encode_float =grib_ibm_to_long;
	  bytes=4;
      break;
    case 1:
      encode_float =grib_ieee_to_long;
	  bytes=4;
      break;
    case 2:
      encode_float =grib_ieee64_to_long;
	  bytes=8;
      break;
    default:
      return GRIB_NOT_IMPLEMENTED;
  }

  Assert (sub_j == sub_k); Assert( sub_j == sub_m);
  Assert (pen_j == pen_k); Assert( pen_j == pen_m);

  n_vals = (pen_j+1)*(pen_j+2);
  d = grib_power(decimal_scale_factor,10) ;

  if(*len != n_vals){
    grib_context_log(a->parent->h->context,GRIB_LOG_ERROR,"COMPLEX_PACKING : wrong number of values, expected %d - got %d",n_vals,*len);
    return GRIB_INTERNAL_ERROR;
  }

  if (pen_j == sub_j) {
	double* values;
	if (d) {
		values=grib_context_malloc_clear(a->parent->h->context,sizeof(double)*n_vals);
		for (i=0;i<n_vals;i++) values[i]=val[i]*d;
	} else {
		values=(double*)val;
	}
	buflen=n_vals*bytes;
	buf  = grib_context_malloc_clear(a->parent->h->context,buflen);
  	grib_ieee_encode_array(a->parent->h->context,values,n_vals,bytes,buf);
	if (d) grib_context_free(a->parent->h->context,values);
	grib_buffer_replace(a, buf, buflen,1,1);
	grib_context_free(a->parent->h->context,buf);
	return 0;
  }

  if(!laplacianOperatorIsSet) {
    laplacianOperator = calculate_pfactor(a->parent->h->context,val,pen_j,sub_j);
    if((ret = grib_set_double_internal(a->parent->h,self->laplacianOperator,laplacianOperator))
          != GRIB_SUCCESS) return ret;
    grib_get_double_internal(a->parent->h,self->laplacianOperator,&laplacianOperator);
  }

/*
printf("PACKING LAPLACE set=%ld value=%.20f\n",laplacianOperatorIsSet,laplacianOperator);
*/
  hsize = 4*(sub_k+1)*(sub_k+2);
  lsize = ((n_vals - ((sub_k+1)*(sub_k+2)))*bits_per_value)/8;

  buflen = hsize+lsize;

  buf  = grib_context_malloc(a->parent->h->context,buflen);
  hres = buf;
  lres = buf+hsize;

  maxv = pen_j+1;

  lpos = 0;
  hpos = 0;

  scals   = (double*) grib_context_malloc(a->parent->h->context,maxv*sizeof(double));
  Assert(scals);

  scals[0] =0;
  for(i=1;i<maxv;i++)
    scals[i] = ((double)pow(i*(i+1),laplacianOperator));


  i=0;

  mmax = 0;
  maxv = pen_j+1;
  i=0;
  lcount=0;
  hcount=0;
  sub_k = sub_j;

  while(maxv>0)
  {
    lup=mmax;

    if(sub_k>=0)
    {
      i   += 2*(sub_k+1);
      lup +=    sub_k+1 ;
      hcount += sub_k+1 ;
      sub_k--;
    }

    for(lcount=hcount; lcount < maxv ; lcount++)
    {
      current_val = ((val[i++]*d) * scals[lup]);
      if(mixmax_unset == 0){
        max = current_val;
        min = current_val;
        mixmax_unset = 1;
      }

      if(current_val > max) max = current_val;
      if(current_val < min) min = current_val;

      current_val = ((val[i++]*d) * scals[lup]);
      if(current_val > max) max = current_val;
      if(current_val < min) min = current_val;

      lup++;
    }
    maxv--;
    hcount=0;
    mmax++;
  }

  if (grib_get_nearest_smaller_value(a->parent->h,self->reference_value,min,&reference_value)
   !=GRIB_SUCCESS) {
    grib_context_log(a->parent->h->context,GRIB_LOG_ERROR,
     "unable to find nearest_smaller_value of %g for %s",min,self->reference_value);
    exit(GRIB_INTERNAL_ERROR);
  }
  binary_scale_factor = grib_get_binary_scale_fact(max,reference_value,bits_per_value,&ret);
  
  if (ret==GRIB_UNDERFLOW) {
	d=0;
	binary_scale_factor = 0;
	reference_value=0;

  }
  s = grib_power(-binary_scale_factor,2);

  /* printf("D : %.30f\n",d); */

  i=0;

  mmax = 0;
  maxv = pen_j+1;
  i=0;
  lcount=0;
  hcount=0;
  sub_k = sub_j;

  while(maxv>0)
  {
    lup=mmax;

    if(sub_k>=0)
    {
      for(hcount=0;hcount<sub_k+1;hcount++)
      {
        if ( GRIBEX_sh_bug_present && hcount==sub_k ) {
          /* _test(val[i]*d*scals[lup],1); */
          grib_encode_unsigned_long(hres, encode_float((val[i++]*d)*scals[lup]) , &hpos, 32);
          /* _test(val[i]*d*scals[lup],1); */
          grib_encode_unsigned_long(hres, encode_float((val[i++]*d)*scals[lup]) , &hpos, 32);
        }else{

          /* _test(val[i]*d,0); */

          grib_encode_unsigned_long(hres, encode_float(val[i++]*d) , &hpos, 32);
          /* _test(val[i]*d,0); */
          grib_encode_unsigned_long(hres, encode_float(val[i++]*d) , &hpos, 32);
        }
        lup++;
      }
      sub_k--;
    }

#if FAST_BIG_ENDIAN
    grib_encode_double_array_complex((maxv-hcount)*2,&(val[i]),bits_per_value,reference_value,&(scals[lup]),d,s,lres,&lpos);
    i+=(maxv-hcount)*2;
#else
	if (bits_per_value % 8) {
		for(lcount=hcount; lcount < maxv ; lcount++)
		{
		  current_val = (((((val[i++]*d) * scals[lup])-reference_value)*s)+0.5);
		  if(current_val < 0)
			grib_context_log(a->parent->h->context,GRIB_LOG_ERROR,
					"COMPLEX_PACKING : negative coput before packing (%g)", current_val);
		  grib_encode_unsigned_longb(lres, current_val, &lpos, bits_per_value);

		  current_val = (((((val[i++]*d) * scals[lup])-reference_value)*s)+0.5);
		  if(current_val < 0)
			grib_context_log(a->parent->h->context,GRIB_LOG_ERROR,
					"COMPLEX_PACKING : negative coput before packing (%g)", current_val);
		  grib_encode_unsigned_longb(lres, current_val, &lpos, bits_per_value);
		  lup++;
		}
	} else {
		for(lcount=hcount; lcount < maxv ; lcount++)
		{
		  current_val = (((((val[i++]*d) * scals[lup])-reference_value)*s)+0.5);
		  if(current_val < 0)
			grib_context_log(a->parent->h->context,GRIB_LOG_ERROR,
				"COMPLEX_PACKING : negative coput before packing (%g)", current_val);
		  grib_encode_unsigned_long(lres, current_val, &lpos, bits_per_value);

		  current_val = (((((val[i++]*d) * scals[lup])-reference_value)*s)+0.5);
		  if(current_val < 0)
			grib_context_log(a->parent->h->context,GRIB_LOG_ERROR,
				"COMPLEX_PACKING : negative coput before packing (%g)", current_val);
		  grib_encode_unsigned_long(lres, current_val, &lpos, bits_per_value);
		  lup++;
		}
	}
#endif

    maxv--;
    hcount=0;
    mmax++;
  }

  if(((hpos/8) != hsize) &&((lpos/8) != lsize))
  {
    grib_context_log(a->parent->h->context,GRIB_LOG_ERROR,
				"COMPLEX_PACKING : Mismatch in packing between high resolution and low resolution part");
    grib_context_free(a->parent->h->context,buf);
    grib_context_free(a->parent->h->context,scals);
    return GRIB_INTERNAL_ERROR;
  }

  buflen = ((hpos + lpos)/8);

  if((ret = grib_set_double_internal(a->parent->h,self->reference_value, reference_value)) != GRIB_SUCCESS)
    return ret;
  {
    /* Make sure we can decode it again */
    double ref = 1e-100;
    grib_get_double_internal(a->parent->h,self->reference_value,&ref);
    Assert(ref == reference_value);
  }

  if((ret = grib_set_long_internal(a->parent->h,self->binary_scale_factor, binary_scale_factor)) != GRIB_SUCCESS)
    return ret;

  grib_buffer_replace(a, buf, buflen,1,1);
  grib_context_free(a->parent->h->context,buf);
  grib_context_free(a->parent->h->context,scals);

  return ret;

}
