Esempio n. 1
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def read_raw(filename):
    """Read *filename* without scaling it afterwards.
    """

    form = XMLFormat(os.path.join(CONFIG_PATH, "eps_avhrrl1b_6.5.xml"))

    grh_dtype = np.dtype([("record_class", "|i1"), ("INSTRUMENT_GROUP", "|i1"),
                          ("RECORD_SUBCLASS", "|i1"),
                          ("RECORD_SUBCLASS_VERSION", "|i1"),
                          ("RECORD_SIZE", ">u4"), ("RECORD_START_TIME", "S6"),
                          ("RECORD_STOP_TIME", "S6")])

    dtypes = []
    cnt = 0
    with open(filename, "rb") as fdes:
        while True:
            grh = np.fromfile(fdes, grh_dtype, 1)
            if not grh:
                break
            rec_class = record_class[int(grh["record_class"])]
            sub_class = grh["RECORD_SUBCLASS"][0]

            expected_size = int(grh["RECORD_SIZE"])
            bare_size = expected_size - grh_dtype.itemsize
            try:
                the_type = form.dtype((rec_class, sub_class))
                the_descr = grh_dtype.descr + the_type.descr
            except KeyError:
                the_type = np.dtype([('unknown', 'V%d' % bare_size)])
            the_descr = grh_dtype.descr + the_type.descr
            the_type = np.dtype(the_descr)
            if the_type.itemsize < expected_size:
                padding = [('unknown%d' % cnt,
                            'V%d' % (expected_size - the_type.itemsize))]
                cnt += 1
                the_descr += padding
            dtypes.append(np.dtype(the_descr))
            fdes.seek(expected_size - grh_dtype.itemsize, 1)

        file_dtype = np.dtype([(str(num), the_dtype)
                               for num, the_dtype in enumerate(dtypes)])
        records = np.memmap(fdes, mode='r', dtype=file_dtype, shape=1)[0]

    return records, form
Esempio n. 2
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def read_raw(filename):
    """Read *filename* without scaling it afterwards.
    """

    form = XMLFormat(os.path.join(CONFIG_PATH, "eps_avhrrl1b_6.5.xml"))

    grh_dtype = np.dtype([("record_class", "|i1"),
                          ("INSTRUMENT_GROUP", "|i1"),
                          ("RECORD_SUBCLASS", "|i1"),
                          ("RECORD_SUBCLASS_VERSION", "|i1"),
                          ("RECORD_SIZE", ">u4"),
                          ("RECORD_START_TIME", "S6"),
                          ("RECORD_STOP_TIME", "S6")])

    record_class = ["Reserved", "mphr", "sphr",
                    "ipr", "geadr", "giadr",
                    "veadr", "viadr", "mdr"]

    records = []

    with open(filename, "rb") as fdes:
        while True:
            grh = np.fromfile(fdes, grh_dtype, 1)
            if not grh:
                break
            rec_class = record_class[int(grh["record_class"])]
            sub_class = grh["RECORD_SUBCLASS"][0]
            offset = fdes.tell()
            try:
                record = np.fromfile(fdes,
                                     form.dtype((rec_class,
                                                 sub_class)),
                                     count=1)
            except KeyError:
                fdes.seek(int(grh["RECORD_SIZE"]) - 20, 1)
            else:
                fdes.seek(offset + int(grh["RECORD_SIZE"]) - 20, 0)
                records.append((rec_class, record, sub_class))

    return records, form
Esempio n. 3
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def read_raw(filename):
    """Read *filename* without scaling it afterwards.
    """

    form = XMLFormat(os.path.join(CONFIG_PATH, "eps_avhrrl1b_6.5.xml"))

    grh_dtype = np.dtype([("record_class", "|i1"),
                          ("INSTRUMENT_GROUP", "|i1"),
                          ("RECORD_SUBCLASS", "|i1"),
                          ("RECORD_SUBCLASS_VERSION", "|i1"),
                          ("RECORD_SIZE", ">u4"),
                          ("RECORD_START_TIME", "S6"),
                          ("RECORD_STOP_TIME", "S6")])

    record_class = ["Reserved", "mphr", "sphr",
                    "ipr", "geadr", "giadr",
                    "veadr", "viadr", "mdr"]

    records = []

    with open(filename, "rb") as fdes:
        while True:
            grh = np.fromfile(fdes, grh_dtype, 1)
            if not grh:
                break
            rec_class = record_class[int(grh["record_class"])]
            sub_class = grh["RECORD_SUBCLASS"][0]
            offset = fdes.tell()
            try:
                record = np.fromfile(fdes,
                                     form.dtype((rec_class,
                                                 sub_class)),
                                     count=1)
            except KeyError:
                fdes.seek(int(grh["RECORD_SIZE"]) - 20, 1)
            else:
                fdes.seek(offset + int(grh["RECORD_SIZE"]) - 20, 0)
                records.append((rec_class, record, sub_class))

    return records, form
Esempio n. 4
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def read_records(filename):
    """Read *filename* without scaling it afterwards."""
    form = XMLFormat(os.path.join(CONFIG_PATH, "eps_avhrrl1b_6.5.xml"))

    grh_dtype = np.dtype([("record_class", "|i1"), ("INSTRUMENT_GROUP", "|i1"),
                          ("RECORD_SUBCLASS", "|i1"),
                          ("RECORD_SUBCLASS_VERSION", "|i1"),
                          ("RECORD_SIZE", ">u4"), ("RECORD_START_TIME", "S6"),
                          ("RECORD_STOP_TIME", "S6")])

    max_lines = np.floor((CHUNK_SIZE**2) / 2048)

    dtypes = []
    cnt = 0
    counts = []
    classes = []
    prev = None
    with open(filename, "rb") as fdes:
        while True:
            grh = np.fromfile(fdes, grh_dtype, 1)
            if grh.size == 0:
                break
            rec_class = record_class[int(grh["record_class"])]
            sub_class = grh["RECORD_SUBCLASS"][0]

            expected_size = int(grh["RECORD_SIZE"])
            bare_size = expected_size - grh_dtype.itemsize
            try:
                the_type = form.dtype((rec_class, sub_class))
                # the_descr = grh_dtype.descr + the_type.descr
            except KeyError:
                the_type = np.dtype([('unknown', 'V%d' % bare_size)])
            the_descr = grh_dtype.descr + the_type.descr
            the_type = np.dtype(the_descr)
            if the_type.itemsize < expected_size:
                padding = [('unknown%d' % cnt,
                            'V%d' % (expected_size - the_type.itemsize))]
                cnt += 1
                the_descr += padding
            new_dtype = np.dtype(the_descr)
            key = (rec_class, sub_class)
            if key == prev:
                counts[-1] += 1
            else:
                dtypes.append(new_dtype)
                counts.append(1)
                classes.append(key)
                prev = key
            fdes.seek(expected_size - grh_dtype.itemsize, 1)

        sections = {}
        offset = 0
        for dtype, count, rec_class in zip(dtypes, counts, classes):
            fdes.seek(offset)
            if rec_class == ('mdr', 2):
                record = da.from_array(np.memmap(fdes,
                                                 mode='r',
                                                 dtype=dtype,
                                                 shape=count,
                                                 offset=offset),
                                       chunks=(max_lines, ))
            else:
                record = np.fromfile(fdes, dtype=dtype, count=count)
            offset += dtype.itemsize * count
            if rec_class in sections:
                logger.debug('Multiple records for ', str(rec_class))
                sections[rec_class] = np.hstack((sections[rec_class], record))
            else:
                sections[rec_class] = record

    return sections, form