eccodes/src/grib_accessor_class_g2grid.c

381 lines
13 KiB
C

/*
* (C) Copyright 2005- ECMWF.
*
* This software is licensed under the terms of the Apache Licence Version 2.0
* which can be obtained at http://www.apache.org/licenses/LICENSE-2.0.
*
* In applying this licence, ECMWF does not waive the privileges and immunities granted to it by
* virtue of its status as an intergovernmental organisation nor does it submit to any jurisdiction.
*/
/*************************************************
* Enrico Fucile
***********************************************/
#include "grib_api_internal.h"
#include <math.h>
/*
This is used by make_class.pl
START_CLASS_DEF
CLASS = accessor
SUPER = grib_accessor_class_double
IMPLEMENTS = unpack_double;pack_double;value_count
IMPLEMENTS = init
MEMBERS=const char* latitude_first
MEMBERS=const char* longitude_first
MEMBERS=const char* latitude_last
MEMBERS=const char* longitude_last
MEMBERS=const char* i_increment
MEMBERS=const char* j_increment
MEMBERS=const char* basic_angle
MEMBERS=const char* sub_division
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 int value_count(grib_accessor*, long*);
static void init(grib_accessor*, const long, grib_arguments*);
static void init_class(grib_accessor_class*);
typedef struct grib_accessor_g2grid
{
grib_accessor att;
/* Members defined in gen */
/* Members defined in double */
/* Members defined in g2grid */
const char* latitude_first;
const char* longitude_first;
const char* latitude_last;
const char* longitude_last;
const char* i_increment;
const char* j_increment;
const char* basic_angle;
const char* sub_division;
} grib_accessor_g2grid;
extern grib_accessor_class* grib_accessor_class_double;
static grib_accessor_class _grib_accessor_class_g2grid = {
&grib_accessor_class_double, /* super */
"g2grid", /* name */
sizeof(grib_accessor_g2grid), /* size */
0, /* inited */
&init_class, /* init_class */
&init, /* init */
0, /* post_init */
0, /* free mem */
0, /* describes himself */
0, /* get length of section */
0, /* get length of string */
&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 array procedures string */
0, /* grib_unpack array 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 */
0, /* clone accessor */
};
grib_accessor_class* grib_accessor_class_g2grid = &_grib_accessor_class_g2grid;
static void init_class(grib_accessor_class* c)
{
c->dump = (*(c->super))->dump;
c->next_offset = (*(c->super))->next_offset;
c->string_length = (*(c->super))->string_length;
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_string_array = (*(c->super))->pack_string_array;
c->unpack_string_array = (*(c->super))->unpack_string_array;
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;
c->make_clone = (*(c->super))->make_clone;
}
/* END_CLASS_IMP */
static void init(grib_accessor* a, const long l, grib_arguments* c)
{
grib_accessor_g2grid* self = (grib_accessor_g2grid*)a;
grib_handle* hand = grib_handle_of_accessor(a);
int n = 0;
self->latitude_first = grib_arguments_get_name(hand, c, n++);
self->longitude_first = grib_arguments_get_name(hand, c, n++);
self->latitude_last = grib_arguments_get_name(hand, c, n++);
self->longitude_last = grib_arguments_get_name(hand, c, n++);
self->i_increment = grib_arguments_get_name(hand, c, n++);
self->j_increment = grib_arguments_get_name(hand, c, n++);
self->basic_angle = grib_arguments_get_name(hand, c, n++);
self->sub_division = grib_arguments_get_name(hand, c, n++);
a->flags |=
GRIB_ACCESSOR_FLAG_EDITION_SPECIFIC |
GRIB_ACCESSOR_FLAG_READ_ONLY;
}
static int value_count(grib_accessor* a, long* count)
{
*count = 6;
return 0;
}
static int unpack_double(grib_accessor* a, double* val, size_t* len)
{
grib_accessor_g2grid* self = (grib_accessor_g2grid*)a;
grib_handle* hand = grib_handle_of_accessor(a);
int ret = 0;
long basic_angle = 0;
long sub_division = 0;
int n = 0;
long v[6];
int i;
if (*len < 6) {
ret = GRIB_ARRAY_TOO_SMALL;
return ret;
}
if ((ret = grib_get_long_internal(hand, self->basic_angle, &basic_angle)) != GRIB_SUCCESS)
return ret;
if ((ret = grib_get_long_internal(hand, self->sub_division, &sub_division)) != GRIB_SUCCESS)
return ret;
if (sub_division == GRIB_MISSING_LONG || sub_division == 0)
sub_division = 1000000;
if (basic_angle == 0)
basic_angle = 1;
n = 0;
if ((ret = grib_get_long_internal(hand, self->latitude_first, &v[n++])) != GRIB_SUCCESS)
return ret;
if ((ret = grib_get_long_internal(hand, self->longitude_first, &v[n++])) != GRIB_SUCCESS)
return ret;
if ((ret = grib_get_long_internal(hand, self->latitude_last, &v[n++])) != GRIB_SUCCESS)
return ret;
if ((ret = grib_get_long_internal(hand, self->longitude_last, &v[n++])) != GRIB_SUCCESS)
return ret;
if (!self->i_increment)
v[n++] = GRIB_MISSING_LONG;
else if ((ret = grib_get_long_internal(hand, self->i_increment, &v[n++])) != GRIB_SUCCESS)
return ret;
if (!self->j_increment) {
v[n++] = GRIB_MISSING_LONG;
} else {
if ((ret = grib_get_long_internal(hand, self->j_increment, &v[n++])) != GRIB_SUCCESS)
return ret;
}
for (i = 0; i < n; i++)
if (v[i] == GRIB_MISSING_LONG)
val[i] = GRIB_MISSING_DOUBLE;
else
val[i] = (double)v[i] / (double)sub_division * (double)basic_angle;
return GRIB_SUCCESS;
}
static long gcd(long a, long b)
{
if (b > a)
return gcd(b, a);
if (b == 0)
return a;
return gcd(b, a % b);
}
static long lcm(long a, long b)
{
return a * b / gcd(a, b);
}
static int is_ok(const double* val, long v[6], double basic_angle, double sub_division)
{
int i;
int ok = 1;
for (i = 0; i < 6; i++) {
if (val[i] == GRIB_MISSING_DOUBLE)
v[i] = GRIB_MISSING_LONG;
else {
double d = (val[i] * sub_division) / basic_angle;
double e;
d = round(d); /* GRIB-941 */
v[i] = d;
e = (v[i] * basic_angle) / sub_division;
/* if(fabs(e - val[i]) >= 1e-6) */
if (fabs(e - val[i]) > 0) {
/* printf("e=%g val=%g diff=%g\n",e,val[i],e-val[i]); */
ok = 0;
}
}
}
return ok;
}
static int trial(const double* val, long v[6], long* basic_angle, long* sub_division)
{
int i = 0;
long ni, nj;
for (i = 0; i < 6; i++)
if (val[i] == GRIB_MISSING_DOUBLE)
return 0;
if (val[4] == 0)
return 0;
if (val[5] == 0)
return 0;
ni = (long)(0.5 + fabs((val[0] - val[2]) / val[4])) + 1;
nj = (long)(0.5 + fabs((val[1] - val[3]) / val[5])) + 1;
*basic_angle = 360;
*sub_division = lcm(ni, nj);
#if 0
printf("ni = %ld, nj = %ld , basic_angle=%ld sub_division = %ld\n",
ni,nj,
*basic_angle,*sub_division);
#endif
if (*sub_division < 0)
return 0;
Assert(*sub_division >= 0);
return is_ok(val, v, *basic_angle, *sub_division);
}
static int pack_double(grib_accessor* a, const double* val, size_t* len)
{
grib_accessor_g2grid* self = (grib_accessor_g2grid*)a;
grib_handle* hand = grib_handle_of_accessor(a);
int ret;
long v[6];
int n;
long basic_angle;
long sub_division;
if (*len < 6) {
ret = GRIB_ARRAY_TOO_SMALL;
return ret;
}
/* printf("pack_double %g %g %g %g %g %g\n",val[0],val[1],val[2],val[3],val[4],val[5]);*/
if (is_ok(val, v, 1, 1000000)) {
basic_angle = 1;
sub_division = 1000000;
}
else if (trial(val, v, &basic_angle, &sub_division)) {
}
else {
basic_angle = 1;
sub_division = 1000000;
if (!is_ok(val, v, basic_angle, sub_division))
grib_context_log(a->context, GRIB_LOG_DEBUG, "Grid cannot be coded with any loss of precision");
}
if (basic_angle == 1 && sub_division == 1000000) {
basic_angle = 0;
sub_division = GRIB_MISSING_LONG;
}
if ((ret = grib_set_long_internal(hand, self->basic_angle, basic_angle)) != GRIB_SUCCESS)
return ret;
if ((ret = grib_set_long_internal(hand, self->sub_division, sub_division)) != GRIB_SUCCESS)
return ret;
n = 0;
if ((ret = grib_set_long_internal(hand, self->latitude_first, v[n++])) != GRIB_SUCCESS)
return ret;
if ((ret = grib_set_long_internal(hand, self->longitude_first, v[n++])) != GRIB_SUCCESS)
return ret;
if ((ret = grib_set_long_internal(hand, self->latitude_last, v[n++])) != GRIB_SUCCESS)
return ret;
if ((ret = grib_set_long_internal(hand, self->longitude_last, v[n++])) != GRIB_SUCCESS)
return ret;
if (!self->i_increment)
n++;
else if ((ret = grib_set_long_internal(hand, self->i_increment, v[n++])) != GRIB_SUCCESS)
return ret;
if (!self->j_increment)
n++;
else if ((ret = grib_set_long_internal(hand, self->j_increment, v[n++])) != GRIB_SUCCESS)
return ret;
return GRIB_SUCCESS;
}