mirror of https://github.com/ecmwf/eccodes.git
89 lines
2.0 KiB
Python
89 lines
2.0 KiB
Python
#
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# (C) Copyright 2005- ECMWF.
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#
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# This software is licensed under the terms of the Apache Licence Version 2.0
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# which can be obtained at http://www.apache.org/licenses/LICENSE-2.0.
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#
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# In applying this licence, ECMWF does not waive the privileges and immunities
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# granted to it by virtue of its status as an intergovernmental organisation
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# nor does it submit to any jurisdiction.
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#
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import sys
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import traceback
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from eccodes import *
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INPUT = "../../data/tp_ecmwf.grib"
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OUTPUT = "p_out.grib_samples.grib"
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VERBOSE = 1 # verbose error reporting
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def example():
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sample_id = codes_grib_new_from_samples("regular_ll_sfc_grib1")
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fin = open(INPUT, "rb")
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fout = open(OUTPUT, "wb")
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keys = {
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"dataDate": 20080104,
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"startStep": 0,
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"endStep": 12,
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"stepType": "accum",
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"table2Version": 2,
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"indicatorOfParameter": 61,
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"decimalPrecision": 2,
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}
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prev_vals = None
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while 1:
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gid = codes_grib_new_from_file(fin)
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if gid is None:
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break
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curr_vals = codes_get_values(gid)
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if prev_vals is None:
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result = prev_vals = curr_vals
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else:
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try:
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# works with NumPy
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result = curr_vals - prev_vals
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except TypeError: # but not with array
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result = curr_vals
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for i in range(len(result)):
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result[i] -= prev_vals[i]
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prev_vals = curr_vals
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keys["startStep"] += 12
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keys["endStep"] += 12
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clone_id = codes_clone(sample_id)
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for key in keys:
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codes_set(clone_id, key, keys[key])
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codes_set_values(clone_id, result * 1000)
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codes_write(clone_id, fout)
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codes_release(gid)
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fin.close()
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fout.close()
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def main():
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try:
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example()
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except CodesInternalError as err:
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if VERBOSE:
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traceback.print_exc(file=sys.stderr)
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else:
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sys.stderr.write(err.msg + "\n")
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return 1
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if __name__ == "__main__":
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sys.exit(main())
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