def randomise_grib(filename):
"""Randomise the data in the given GRIB file."""
in_file = open(filename, "rb")
out_file = open("out.grib", "wb")
while True:
grib_message = gribapi.grib_new_from_file(in_file)
if not grib_message:
break
values = gribapi.grib_get_double_array(grib_message, "values")
values = numpy.random.rand(len(values))
gribapi.grib_set_double_array(grib_message, "values", values)
gribapi.grib_write(grib_message, out_file)
os.remove(filename)
os.rename("out.grib", filename)
def write_lsm(gribfield_mod, input_path_oifs, output_path_oifs, exp_name_oifs,
grid_name_oce, num_fields, gid):
'''
This function copies the input gribfile to the output folder and modifies
it by writing the whole gribfield_mod, including the altered land sea mask
and soil type fields into the new file
'''
input_file_oifs = input_path_oifs + 'ICMGG' + exp_name_oifs + 'INIT'
output_file_oifs = output_path_oifs + 'ICMGG' + exp_name_oifs + 'INIT_' + grid_name_oce
copy2(input_file_oifs, output_file_oifs)
with open(output_file_oifs, 'r+') as f:
for i in range(num_fields):
gribapi.grib_set_values(gid[i], gribfield_mod[i])
gribapi.grib_write(gid[i], f)
gribapi.grib_release(gid[i])
def randomise_grib(filename):
"""Randomise the data in the given GRIB file."""
in_file = open(filename, "rb")
out_file = open("out.grib", "wb")
while True:
grib_message = gribapi.grib_new_from_file(in_file)
if not grib_message:
break
values = gribapi.grib_get_double_array(grib_message, "values")
values = numpy.random.rand(len(values))
gribapi.grib_set_double_array(grib_message, "values", values)
gribapi.grib_write(grib_message, out_file)
os.remove(filename)
os.rename("out.grib", filename)
def test_warn_unknown_pdts(self):
# Test loading of an unrecognised GRIB Product Definition Template.
# Get a temporary file by name (deleted afterward by context).
with self.temp_filename() as temp_gribfile_path:
# Write a test grib message to the temporary file.
with open(temp_gribfile_path, 'wb') as temp_gribfile:
grib_message = gribapi.grib_new_from_samples('GRIB2')
# Set the PDT to something unexpected.
gribapi.grib_set_long(grib_message,
'productDefinitionTemplateNumber', 5)
gribapi.grib_write(grib_message, temp_gribfile)
# Load the message from the file as a cube.
cube_generator = iris_grib.load_cubes(temp_gribfile_path)
with self.assertRaises(iris.exceptions.TranslationError) as te:
cube = next(cube_generator)
self.assertEqual(
'Product definition template [5]'
' is not supported', str(te.exception))
def test_warn_unknown_pdts(self):
# Test loading of an unrecognised GRIB Product Definition Template.
# Get a temporary file by name (deleted afterward by context).
with self.temp_filename() as temp_gribfile_path:
# Write a test grib message to the temporary file.
with open(temp_gribfile_path, 'wb') as temp_gribfile:
grib_message = gribapi.grib_new_from_samples('GRIB2')
# Set the PDT to something unexpected.
gribapi.grib_set_long(
grib_message, 'productDefinitionTemplateNumber', 5)
gribapi.grib_write(grib_message, temp_gribfile)
# Load the message from the file as a cube.
cube_generator = iris.fileformats.grib.load_cubes(
temp_gribfile_path)
with self.assertRaises(iris.exceptions.TranslationError) as te:
cube = next(cube_generator)
self.assertEqual('Product definition template [5]'
' is not supported', str(te.exception))
def test_warn_unknown_pdts(self):
# Test loading of an unrecognised GRIB Product Definition Template.
# Get a temporary file by name (deleted afterward by context).
with self.temp_filename() as temp_gribfile_path:
# Write a test grib message to the temporary file.
with open(temp_gribfile_path, 'wb') as temp_gribfile:
grib_message = gribapi.grib_new_from_samples('GRIB2')
# Set the PDT to something unexpected.
gribapi.grib_set_long(grib_message,
'productDefinitionTemplateNumber', 5)
gribapi.grib_write(grib_message, temp_gribfile)
# Load the message from the file as a cube.
cube_generator = iris.fileformats.grib.load_cubes(
temp_gribfile_path)
cube = next(cube_generator)
# Check the cube has an extra "warning" attribute.
self.assertEqual(
cube.attributes['GRIB_LOAD_WARNING'],
'unsupported GRIB2 ProductDefinitionTemplate: #4.5')
def save_messages(messages, target, append=False):
"""
Save messages to a GRIB2 file.
The messages will be released as part of the save.
Args:
* messages:
An iterable of grib_api message IDs.
* target:
A filename or open file handle.
Kwargs:
* append:
Whether to start a new file afresh or add the cube(s) to the end of
the file. Only applicable when target is a filename, not a file
handle. Default is False.
"""
# grib file (this bit is common to the pp and grib savers...)
if isinstance(target, str):
grib_file = open(target, "ab" if append else "wb")
elif hasattr(target, "write"):
if hasattr(target, "mode") and "b" not in target.mode:
raise ValueError("Target not binary")
grib_file = target
else:
raise ValueError("Can only save grib to filename or writable")
try:
for message in messages:
gribapi.grib_write(message, grib_file)
gribapi.grib_release(message)
finally:
# (this bit is common to the pp and grib savers...)
if isinstance(target, str):
grib_file.close()
def save_messages(messages, target, append=False):
"""
Save messages to a GRIB2 file.
The messages will be released as part of the save.
Args:
* messages:
An iterable of grib_api message IDs.
* target:
A filename or open file handle.
Kwargs:
* append:
Whether to start a new file afresh or add the cube(s) to the end of
the file. Only applicable when target is a filename, not a file
handle. Default is False.
"""
# grib file (this bit is common to the pp and grib savers...)
if isinstance(target, six.string_types):
grib_file = open(target, "ab" if append else "wb")
elif hasattr(target, "write"):
if hasattr(target, "mode") and "b" not in target.mode:
raise ValueError("Target not binary")
grib_file = target
else:
raise ValueError("Can only save grib to filename or writable")
try:
for message in messages:
gribapi.grib_write(message, grib_file)
gribapi.grib_release(message)
finally:
# (this bit is common to the pp and grib savers...)
if isinstance(target, six.string_types):
grib_file.close()
def test_warn_unknown_pdts(self):
# Test loading of an unrecognised GRIB Product Definition Template.
# Get a temporary file by name (deleted afterward by context).
with self.temp_filename() as temp_gribfile_path:
# Write a test grib message to the temporary file.
with open(temp_gribfile_path, 'wb') as temp_gribfile:
grib_message = gribapi.grib_new_from_samples('GRIB2')
# Set the PDT to something unexpected.
gribapi.grib_set_long(
grib_message, 'productDefinitionTemplateNumber', 5)
gribapi.grib_write(grib_message, temp_gribfile)
# Load the message from the file as a cube.
cube_generator = iris.fileformats.grib.load_cubes(
temp_gribfile_path)
cube = cube_generator.next()
# Check the cube has an extra "warning" attribute.
self.assertEqual(
cube.attributes['GRIB_LOAD_WARNING'],
'unsupported GRIB2 ProductDefinitionTemplate: #4.5'
)
def write(self, file_object_):
gribapi.grib_write(self.record, file_object_)
def write(self, outfile=None):
"""Write message to file."""
if not outfile:
# This is a hack because the API does not accept inheritance
outfile = self.grib_file.file_handle
gribapi.grib_write(self.gid, outfile)
def save(source, target, append=False, sample_file=_sample_file):
"""
Takes a dataset (source) and writes its contents
as grib 1 to file-like target. Grib 1 is used (instead
of grib 2) because some older forecast visualization
software can't read grib 2.
This is a heavily modified but none-the-less derivative of
the grib saving functions from the iris package.
Parameters
----------
source : Dataset
A netcdf-like file holding the dataset we want to write
as grib. This must contain time, longitude and latitude
coordinates in order to infer the grib grid and time params
target : string path or file-like
Where the contents should be written. If target is a string
the file is created or appended to.
append : boolean
When creating a new file from string you can optionally
append to the file.
"""
if not _has_gribapi:
raise ImportError("gripapi is required to write grib files.")
if isinstance(target, basestring):
grib_file = open(target, "ab" if append else "wb")
elif hasattr(target, "write"):
if hasattr(target, "mode") and "b" not in target.mode:
raise ValueError("Target not binary")
grib_file = target
else:
raise ValueError("Can only save grib to filename or writable")
if not 'latitude' in source.variables or not 'longitude' in source.variables:
raise ValueError("Did not find either latitude or longitude.")
if source['latitude'].ndim != 1 or source['longitude'].ndim != 1:
raise ValueError("Latitude and Longitude should be regular.")
if not 'time' in source.variables:
raise ValueError("Expected time coordinate")
# sort the lats and lons
source = source.indexed(latitude=np.argsort(source['latitude'].values))
lons = source['longitude'].values
if np.any(np.abs(np.diff(lons)) > 180.):
# the latitudes must cross the dateline since we only allow 180
# degree wide bounding boxes, and there is more than a 180 degree
# difference between longitudes. Instead we try converting to
# 0 to 360 degree longitudes before sorting.
lons = np.mod(lons, 360)
if np.any(np.abs(np.diff(lons)) > 180.):
# TODO: I'm sure theres a way to deal with arbitrary longitude
# specifications for global data ... but its not a high priority
# so that will wait for later.
raise ValueError("Longitudes span more than 180 degrees and the dateline?")
source['longitude'].values[:] = lons
source = source.indexed(longitude=np.argsort(lons))
# iterate over variables, unless they are considered
# auxiliary variables (ie, variables used by slocum
# but not in grib files).
auxilary_variables = ['wind_speed', 'wind_from_direction']
for single_var in (v for k, v in source.noncoordinates.iteritems()
if not k in auxilary_variables):
# then iterate over time slices
iter_time = (single_var.indexed(**{'time': [i]})
for i in range(single_var.coordinates['time'].size))
for obj in iter_time:
# Save this slice to the grib file
gribapi.grib_gribex_mode_off()
if sample_file is not None and os.path.exists(sample_file):
with open(sample_file, 'r') as f:
grib_message = gribapi.grib_new_from_file(f)
logger.info("Created grib message from file %s" % sample_file)
else:
logger.info("Creating grib message from gribapi sample: GRIB1")
grib_message = gribapi.grib_new_from_samples("GRIB1")
set_time(obj, grib_message)
set_product(obj, grib_message)
set_grid(obj, grib_message)
set_data(obj, grib_message)
gribapi.grib_write(grib_message, grib_file)
gribapi.grib_release(grib_message)
# if target was a string then we have to close the file we
# created, otherwise leave that up to the user.
if isinstance(target, basestring):
grib_file.close()
def write(self, outfile=None):
"""Write message to file."""
if not outfile:
# This is a hack because the API does not accept inheritance
outfile = self.grib_file.file_handle
gribapi.grib_write(self.gid, outfile)
def write_record(msgid, files):
gribapi.grib_write(msgid, files[0])
