AsType

class numcodecs.astype.AsType(encode_dtype, decode_dtype)

Filter to convert data between different types.

Parameters:

encode_dtypedtype

Data type to use for encoded data.

decode_dtypedtype, optional

Data type to use for decoded data.

Notes

If encode_dtype is of lower precision than decode_dtype, please be aware that data loss can occur by writing data to disk using this filter. No checks are made to ensure the casting will work in that direction and data corruption will occur.

Examples

>>> import numcodecs
>>> import numpy as np
>>> x = np.arange(100, 120, 2, dtype=np.int8)
>>> x
array([100, 102, 104, 106, 108, 110, 112, 114, 116, 118], dtype=int8)
>>> f = numcodecs.AsType(encode_dtype=x.dtype, decode_dtype=np.int16)
>>> y = f.decode(x)
>>> y
array([100, 102, 104, 106, 108, 110, 112, 114, 116, 118], dtype=int16)
>>> z = f.encode(y)
>>> z
array([100, 102, 104, 106, 108, 110, 112, 114, 116, 118], dtype=int8)

codec_id: str | None = 'astype'

Codec identifier.

encode(buf)

Encode data in buf.

Parameters:

bufbuffer-like

Data to be encoded. May be any object supporting the new-style buffer protocol.

Returns:

encbuffer-like

Encoded data. May be any object supporting the new-style buffer protocol.

decode(buf, out=None)

Decode data in buf.

Parameters:

bufbuffer-like

Encoded data. May be any object supporting the new-style buffer protocol.

outbuffer-like, optional

Writeable buffer to store decoded data. N.B. if provided, this buffer must be exactly the right size to store the decoded data.

Returns:

decbuffer-like

Decoded data. May be any object supporting the new-style buffer protocol.

get_config()

Return a dictionary holding configuration parameters for this codec. Must include an ‘id’ field with the codec identifier. All values must be compatible with JSON encoding.

classmethod from_config(config)

Instantiate codec from a configuration object.