CorrelateShift

class of dascore.proc.correlate
inherits from: PatchProcessor, DascoreBaseModel, pydantic.main.BaseModel

CorrelateShift(
    *args ,
    dim: Any ,
    undo_weighting: Any = True,
)-> None

Apply a shift to the patch data to undo correlation in frequency domain.

Also adds the appropriate coordinate prefixed with “lag” and has a datatype of float.

Parameters

Parameter	Description
patch	The input patch
dim	The dimension name that was correlated in the freq. domain.
undo_weighting	If True, also undo the weighting artifact caused by DASCore’s dft weighting. This is done by simply dividing by the coordinate step. See dft note for more details.

Note

A product of transforms is a correlation circular over the transformed length, but idft trims a padded transform back to the original length, which drops the most negative lags. Transform with pad=False, or pad first with patch.pad(time="correlate"), as below.

Examples

import dascore as dc
patch = dc.get_example_patch()

# Example 1
# An auto-correlation of the example patch
dft = patch.dft("time", real=True, pad=False)
dft_sq = dft * dft.conj()
idft = dft_sq.idft()
auto_patch = idft.correlate_shift(dim="time")

Methods

Name	Description
check	Refuse a patch which does not carry what the operation needs.
get_metadata	Return metadata with the lag coordinate, and the axis and step.
kernel	Return the data shifted so zero lag is central, divided by the step.
model_copy	Copy the model, dropping cached values the update invalidates.
new	Create new instance with some attributed updated.
correlate_shift	Apply a shift to the patch data to undo correlation in frequency domain.
reconcile	Return metadata or a patch holding the final data; default as is.
run	Run the operation: check, get_metadata, kernel, reconcile, record.