def test_grib_nearest():
gid = eccodes.codes_grib_new_from_samples("reduced_gg_ml_grib2")
lat, lon = 30, -20
nearest = eccodes.codes_grib_find_nearest(gid, lat, lon)[0]
assert nearest.index == 1770
lat, lon = 10, 0
nearest = eccodes.codes_grib_find_nearest(gid, lat, lon)[0]
assert nearest.index == 2545
lat, lon = 10, 20
nearest = eccodes.codes_grib_find_nearest(gid, lat, lon, False, 4)
expected_indexes = (2553, 2552, 2425, 2424)
returned_indexes = (
nearest[0].index,
nearest[1].index,
nearest[2].index,
nearest[3].index,
)
assert sorted(expected_indexes) == sorted(returned_indexes)
# Cannot do more than 4 nearest neighbours
with pytest.raises(ValueError):
eccodes.codes_grib_find_nearest(gid, lat, lon, False, 5)
eccodes.codes_release(gid)
def nearest_parallel_step(chunk, gid, mv):
lat, lon, x, y = chunk
idx = int_fill_value
if not (lon <= -1.0e+10 or lon == mv):
try:
n_nearest = eccodes.codes_grib_find_nearest(
gid, lat.item(), lon.item())
except eccodes.GribInternalError:
x = int_fill_value
y = int_fill_value
else:
idx = n_nearest[0]['index']
return int(x), int(y), idx
def cli(file_path):
with open(file_path, 'rb') as f:
handle = eccodes.codes_grib_new_from_file(f, headers_only=False)
while handle is not None:
date = eccodes.codes_get(handle, "dataDate")
type_of_level = eccodes.codes_get(handle, "typeOfLevel")
level = eccodes.codes_get(handle, "level")
points = eccodes.codes_grib_find_nearest(handle, 39.92, 116.46,
False, 1)
point = points[0]
print(date, type_of_level, level, " :", point.lat, point.lon,
point.value, point.distance)
eccodes.codes_release(handle)
handle = eccodes.codes_grib_new_from_file(f, headers_only=False)
def invdist_parallel_step(chunk, gid, mv):
lat, lon, x, y = chunk
idx1 = idx2 = idx3 = idx4 = int_fill_value
inv1 = inv2 = inv3 = inv4 = np.NaN
if not (lon < -1.0e+10 or lon == mv):
try:
n_nearest = eccodes.codes_grib_find_nearest(gid,
lat.item(),
lon.item(),
npoints=4)
except eccodes.GribInternalError:
# tipically "out of grid" error
x = int_fill_value
y = int_fill_value
else:
inv1, inv2, inv3, inv4, idx1, idx2, idx3, idx4 = _compute_coeffs_and_idxs(
n_nearest)
return x, y, idx1, idx2, idx3, idx4, inv1, inv2, inv3, inv4
def grib_nearest(gid, target_lats, target_lons, mv):
num_cells = target_lons.size
indices = np.indices(target_lons.shape)
valid_target_coords = (target_lons > -1.0e+10) & (target_lons != mv)
xs = np.where(valid_target_coords, indices[0], int_fill_value).ravel()
ys = np.where(valid_target_coords, indices[1], int_fill_value).ravel()
idxs = empty(num_cells, fill_value=int_fill_value, dtype=int)
back_char, progress_step = progress_step_and_backchar(num_cells)
format_progress = '{}Nearest neighbour interpolation: {}/{} [outs: {}] ({}%)'.format
i = 0
outs = 0
stdout.write('Start interpolation: {}\n'.format(now_string()))
stdout.write(format_progress(back_char, 0, num_cells, outs, 0))
stdout.flush()
for lat, lon in zip(target_lats.flat, target_lons.flat):
if i % progress_step == 0:
stdout.write(
format_progress(back_char, i, num_cells, outs,
i * 100. / num_cells))
stdout.flush()
if not (lon <= -1.0e+10 or lon == mv):
try:
n_nearest = eccodes.codes_grib_find_nearest(
gid, lat.item(), lon.item())
except eccodes.GribInternalError:
outs += 1
xs[i] = int_fill_value
ys[i] = int_fill_value
else:
idxs[i] = n_nearest[0]['index']
i += 1
stdout.write('{}{:>100}'.format(back_char, ' '))
stdout.write(format_progress(back_char, i, num_cells, outs, 100))
stdout.write('End interpolation: {}\n\n'.format(now_string()))
stdout.flush()
return (xs[xs != int_fill_value], ys[ys != int_fill_value],
idxs[idxs != int_fill_value])
def grib_invdist(gid, target_lats, target_lons, mv):
num_cells = target_lons.size
indices = np.indices(target_lons.shape)
valid_target_coords = (target_lons > -1.0e+10) & (target_lons != mv)
xs = np.where(valid_target_coords, indices[0], int_fill_value).ravel()
ys = np.where(valid_target_coords, indices[1], int_fill_value).ravel()
idxs1 = empty(num_cells, fill_value=int_fill_value, dtype=int)
idxs2 = empty(num_cells, fill_value=int_fill_value, dtype=int)
idxs3 = empty(num_cells, fill_value=int_fill_value, dtype=int)
idxs4 = empty(num_cells, fill_value=int_fill_value, dtype=int)
invs1 = empty(num_cells)
invs2 = empty(num_cells)
invs3 = empty(num_cells)
invs4 = empty(num_cells)
format_progress = '{}Inverse distance interpolation: {}/{} [outs: {}] ({}%)'.format
i = 0
outs = 0
back_char, progress_step = progress_step_and_backchar(num_cells)
stdout.write('Start interpolation: {}\n'.format(now_string()))
stdout.write(format_progress(back_char, 0, num_cells, outs, 0))
stdout.flush()
for lat, lon in zip(target_lats.flat, target_lons.flat):
if i % progress_step == 0:
stdout.write(
format_progress(back_char, i, num_cells, outs,
i * 100. / num_cells))
stdout.flush()
if not (lon < -1.0e+10 or lon == mv):
try:
n_nearest = eccodes.codes_grib_find_nearest(gid,
lat.item(),
lon.item(),
npoints=4)
except eccodes.GribInternalError:
# tipically "out of grid" error
outs += 1
xs[i] = int_fill_value
ys[i] = int_fill_value
else:
invs1[i], invs2[i], invs3[i], invs4[i], idxs1[i], idxs2[
i], idxs3[i], idxs4[i] = _compute_coeffs_and_idxs(
n_nearest)
i += 1
# variables seems unused but they are in numexpress expressions (see ne.evaluate())
# DO NOT DELETE
invs1 = invs1[~np.isnan(invs1)]
invs2 = invs2[~np.isnan(invs2)]
invs3 = invs3[~np.isnan(invs3)]
invs4 = invs4[~np.isnan(invs4)]
sums = ne.evaluate('invs1 + invs2 + invs3 + invs4')
coeffs1 = ne.evaluate('invs1 / sums')
coeffs2 = ne.evaluate('invs2 / sums')
coeffs3 = ne.evaluate('invs3 / sums')
coeffs4 = ne.evaluate('invs4 / sums')
stdout.write('{}{:>100}'.format(back_char, ' '))
stdout.write(format_progress(back_char, i, num_cells, outs, 100))
stdout.write('End interpolation: {}\n\n'.format(now_string()))
stdout.flush()
return (xs[xs != int_fill_value], ys[ys != int_fill_value],
idxs1[idxs1 != int_fill_value], idxs2[idxs2 != int_fill_value],
idxs3[idxs3 != int_fill_value], idxs4[idxs4 != int_fill_value],
coeffs1, coeffs2, coeffs3, coeffs4)
def nearest_value_func(gid, args):
lat, lon = args
nearest = codes_grib_find_nearest(gid, lat, lon)[0]
return lat, lon, nearest.value