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ECC-499: function grib_nearest_find to get the indexes but not the values

This commit is contained in:
Shahram Najm 2019-12-12 17:33:56 +00:00
parent 0f0f3d1219
commit b2a1cc813a
7 changed files with 101 additions and 14 deletions
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1
examples/C/CMakeLists.txt
View File

@ -83,6 +83,7 @@ list( APPEND tests_extra
grib_set_bitmap
grib_list
grib_get_data
grib_nearest
grib_nearest_multiple
set_missing
bufr_attributes

34
examples/C/grib_nearest.c
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@ -21,7 +21,7 @@
#include "eccodes.h"
static void usage(const char* prog) {
printf("Usage: %s grib_file grib_file ...\n",prog);
printf("Usage: %s [-n] grib_file grib_file ...\n",prog);
exit(1);
}
@ -31,6 +31,7 @@ int main(int argc, char** argv)
long step=0;
size_t nfiles;
int i=0;
int no_values = 0; /* Default: decode the values */
codes_fieldset* set=NULL;
codes_handle* h=NULL;
char param[20]={0,};
@ -41,26 +42,35 @@ int main(int argc, char** argv)
double distances[4]={0,};
int indexes[4]={0,};
char* order_by="param,step";
double* pValues = values;
size_t size=4;
double lat=-40,lon=15;
int mode=0;
int count;
int filearg_offset = 1;
char** filenames;
codes_nearest* nearest=NULL;
if (argc < 2) usage(argv[0]);
nfiles=argc-1;
if (strcmp(argv[1],"-n")==0) {
no_values = 1; /* No values decoding. Just indexes, distances etc */
nfiles -= 1;
pValues = NULL;
filearg_offset++;
}
filenames=(char**)malloc(sizeof(char*)*nfiles);
for (i=0;i<nfiles;i++)
filenames[i]=(char*)strdup(argv[i+1]);
filenames[i]=(char*)strdup(argv[i+filearg_offset]);
set=codes_fieldset_new_from_files(0,filenames,nfiles,0,0,0,order_by,&err);
CODES_CHECK(err,0);
printf("\nordering by %s\n",order_by);
printf("\n%d fields in the fieldset\n",codes_fieldset_count(set));
printf("ordering by %s\n",order_by);
printf("%d fields in the fieldset\n",codes_fieldset_count(set));
printf("n,step,param\n");
mode=CODES_NEAREST_SAME_GRID | CODES_NEAREST_SAME_POINT;
@ -74,10 +84,16 @@ int main(int argc, char** argv)
printf("%d %ld %s ",count,step,param);
if (!nearest) nearest=codes_grib_nearest_new(h,&err);
CODES_CHECK(err,0);
CODES_CHECK(codes_grib_nearest_find(nearest,h,lat,lon,mode,lats,lons,values,distances,indexes,&size),0);
printf("\nIdx\tlat\tlon\tdist\tval\n");
for (i=0;i<4;i++) printf("%d\t%.2f\t%.2f\t%g\t%g\n",
(int)indexes[i],lats[i],lons[i],distances[i],values[i]);
CODES_CHECK(codes_grib_nearest_find(nearest,h,lat,lon,mode,lats,lons,pValues,distances,indexes,&size),0);
if (no_values) {
printf("\nIdx\tlat\tlon\tdist\n");
for (i=0;i<4;i++) printf("%d\t%.2f\t%.2f\t%g\n",
(int)indexes[i],lats[i],lons[i],distances[i]);
} else {
printf("\nIdx\tlat\tlon\tdist\tval\n");
for (i=0;i<4;i++) printf("%d\t%.2f\t%.2f\t%g\t%g\n",
(int)indexes[i],lats[i],lons[i],distances[i],values[i]);
}
printf("\n");
codes_handle_delete(h);

53
examples/C/grib_nearest.sh Executable file
View File

@ -0,0 +1,53 @@
#!/bin/sh
# Copyright 2005-2019 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.
#
. ./include.sh
label="grib_nearest"
temp=$label.temp
tempRef=$label.ref
input_grb=${data_dir}/reduced_gaussian_pressure_level.grib1
# Nearest with decoding the data values
# --------------------------------------
${examples_dir}/c_grib_nearest $input_grb > $temp
cat > $tempRef <<EOF
ordering by param,step
1 fields in the fieldset
n,step,param
1 0 t
Idx lat lon dist val
4839 -40.46 18.00 259.679 285.527
4838 -40.46 15.00 51.5268 284.074
4719 -37.67 18.00 366.445 289.621
4718 -37.67 15.00 258.597 289.027
EOF
diff $tempRef $temp
# Nearest without decoding the data values
# ----------------------------------------
${examples_dir}/c_grib_nearest -n $input_grb > $temp
cat > $tempRef <<EOF
ordering by param,step
1 fields in the fieldset
n,step,param
1 0 t
Idx lat lon dist
4839 -40.46 18.00 259.679
4838 -40.46 15.00 51.5268
4719 -37.67 18.00 366.445
4718 -37.67 15.00 258.597
EOF
diff $tempRef $temp
# Clean up
rm -f $temp $tempRef

15
src/grib_nearest.c
View File

@ -16,6 +16,9 @@
#include "grib_api_internal.h"
/* Note: The 'values' argument can be NULL in which case the data section will not be decoded
* See ECC-499
*/
int grib_nearest_find(
grib_nearest *nearest, const grib_handle* ch,
double inlat, double inlon,
@ -147,17 +150,22 @@ int grib_nearest_find_multiple(
double qoutlats[4]={0,};
double qoutlons[4]={0,};
double qvalues[4]={0,};
double* rvalues = NULL;
int qindexes[4]={0,};
int ret=0;
long i=0;
size_t len=4;
int flags=GRIB_NEAREST_SAME_GRID | GRIB_NEAREST_SAME_DATA;
if (values) rvalues = qvalues;
nearest=grib_nearest_new(h,&ret);
if (ret!=GRIB_SUCCESS) return ret;
if (is_lsm) {
int noland=1;
/* ECC-499: In land-sea mask mode, 'values' cannot be NULL because we need to query whether >= 0.5 */
Assert(values);
for (i=0;i<npoints;i++) {
ret=grib_nearest_find(nearest,h,inlats[i],inlons[i],flags,qoutlats,qoutlons,
qvalues,qdistances,qindexes,&len);
@ -181,9 +189,10 @@ int grib_nearest_find_multiple(
}
} else {
/* ECC-499: 'values' can be NULL */
for (i=0;i<npoints;i++) {
ret=grib_nearest_find(nearest,h,inlats[i],inlons[i],flags,qoutlats,qoutlons,
qvalues,qdistances,qindexes,&len);
rvalues,qdistances,qindexes,&len);
min=qdistances[0];
for (ii=0;ii<4;ii++) {
if ((min >= qdistances[ii])) {
@ -193,7 +202,9 @@ int grib_nearest_find_multiple(
}
*poutlats=qoutlats[idx];poutlats++;
*poutlons=qoutlons[idx];poutlons++;
*pvalues=qvalues[idx];pvalues++;
if (values) {
*pvalues=qvalues[idx];pvalues++;
}
*pdistances=qdistances[idx];pdistances++;
*pindexes=qindexes[idx];pindexes++;
}

4
src/grib_nearest_class_latlon_reduced.c
View File

@ -328,7 +328,9 @@ static int find(grib_nearest* nearest, grib_handle* h,
distances[kk]=self->distances[kk];
outlats[kk]=self->lats[self->j[jj]];
outlons[kk]=self->lons[self->k[kk]];
grib_get_double_element_internal(h,self->values_key,self->k[kk],&(values[kk]));
if (values) { /* ECC-499 */
grib_get_double_element_internal(h,self->values_key,self->k[kk],&(values[kk]));
}
indexes[kk]=self->k[kk];
kk++;
}

4
src/grib_nearest_class_reduced.c
View File

@ -382,7 +382,9 @@ static int find(grib_nearest* nearest, grib_handle* h,
distances[kk]=self->distances[kk];
outlats[kk]=self->lats[self->j[jj]];
outlons[kk]=self->lons[self->k[kk]];
grib_get_double_element_internal(h,self->values_key,self->k[kk],&(values[kk]));
if (values) { /* ECC-499 */
grib_get_double_element_internal(h,self->values_key,self->k[kk],&(values[kk]));
}
indexes[kk]=self->k[kk];
kk++;
}

4
src/grib_nearest_class_regular.c
View File

@ -420,7 +420,9 @@ static int find(grib_nearest* nearest, grib_handle* h,
outlats[kk] = new_lat;
outlons[kk] = new_lon;
}
grib_get_double_element_internal(h,self->values_key,self->k[kk],&(values[kk]));
if (values) { /* ECC-499 */
grib_get_double_element_internal(h,self->values_key,self->k[kk],&(values[kk]));
}
/* Using the brute force approach described above */
/* Assert(self->k[kk] < nvalues); */
/* values[kk]=nearest->values[self->k[kk]]; */