Container for filter properties. This class is meant to serve as a container that keeps information about the filter properties associated with the chunked leaves, that is Table, CArray, EArray and VLArray. Instances of this class can be directly compared for equality. Paramet
| 48 | |
| 49 | |
| 50 | class Filters: |
| 51 | """Container for filter properties. |
| 52 | |
| 53 | This class is meant to serve as a container that keeps information about |
| 54 | the filter properties associated with the chunked leaves, that is Table, |
| 55 | CArray, EArray and VLArray. |
| 56 | |
| 57 | Instances of this class can be directly compared for equality. |
| 58 | |
| 59 | Parameters |
| 60 | ---------- |
| 61 | complevel : int |
| 62 | Specifies a compression level for data. The allowed |
| 63 | range is 0-9. A value of 0 (the default) disables |
| 64 | compression. |
| 65 | complib : str |
| 66 | Specifies the compression library to be used. Right now, 'zlib' (the |
| 67 | default), 'lzo', 'bzip2', 'blosc' and 'blosc2' are supported. |
| 68 | Additional compressors for Blosc like 'blosc:blosclz' ('blosclz' is |
| 69 | the default in case the additional compressor is not specified), |
| 70 | 'blosc:lz4', 'blosc:lz4hc', 'blosc:zlib' and 'blosc:zstd' are |
| 71 | supported too. |
| 72 | Also, additional compressors for Blosc2 like 'blosc2:blosclz' |
| 73 | ('blosclz' is the default in case the additional compressor is not |
| 74 | specified), 'blosc2:lz4', 'blosc2:lz4hc', 'blosc2:zlib' and |
| 75 | 'blosc2:zstd' are supported too. |
| 76 | Specifying a compression library which is not available |
| 77 | in the system issues a FiltersWarning and sets the library to the |
| 78 | default one. |
| 79 | shuffle : bool |
| 80 | Whether to use the *Shuffle* filter in the HDF5 library. |
| 81 | This is normally used to improve the compression ratio. |
| 82 | A false value disables shuffling and a true one enables |
| 83 | it. The default value depends on whether compression is |
| 84 | enabled or not; if compression is enabled, shuffling defaults |
| 85 | to be enabled, else shuffling is disabled. Shuffling can only |
| 86 | be used when compression is enabled. |
| 87 | bitshuffle : bool |
| 88 | Whether to use the *BitShuffle* filter in the Blosc/Blosc2 |
| 89 | libraries. This is normally used to improve the compression |
| 90 | ratio. A false value disables bitshuffling and a true one |
| 91 | enables it. The default value is disabled. |
| 92 | fletcher32 : bool |
| 93 | Whether to use the *Fletcher32* filter in the HDF5 library. |
| 94 | This is used to add a checksum on each data chunk. A false |
| 95 | value (the default) disables the checksum. |
| 96 | least_significant_digit : int |
| 97 | If specified, data will be truncated (quantized). In conjunction |
| 98 | with enabling compression, this produces 'lossy', but |
| 99 | significantly more efficient compression. For example, if |
| 100 | *least_significant_digit=1*, data will be quantized using |
| 101 | ``around(scale*data)/scale``, where ``scale = 2**bits``, and |
| 102 | bits is determined so that a precision of 0.1 is retained (in |
| 103 | this case bits=4). Default is *None*, or no quantization. |
| 104 | |
| 105 | .. note:: |
| 106 | |
| 107 | quantization is only applied if some form of compression is |
no outgoing calls
no test coverage detected