pulsarbat.readers.BaseReader

class pulsarbat.readers.BaseReader(*, shape, dtype, signal_type=<class 'pulsarbat.core.Signal'>, sample_rate, start_time=None, **signal_kwargs)

Base class for readers.

Subclasses must either implement the _read_array() method if using the default .read() implementation, or implement their own .read() method.

Parameters

shapetuple of int

Signal shape.

dtypedtype

Data-type of signal data.

signal_typesubclass of Signal, default: Signal

Type of signal that will be returned by read().

sample_rateQuantity

The number of samples per second. Must be in units of frequency.

start_timeTime, optional

Timestamp at first sample of signal data. Default is None.

**signal_kwargs

Additional kwargs to pass on to signal_type when creating a Signal object.

Attributes

dt	Sample spacing (1 / sample_rate).
dtype	Data-type of data.
ndim	Number of dimensions in data.
sample_rate	Sample rate of the signal data.
sample_shape	Shape of a sample.
shape	Shape of data.
start_time	Timestamp at first sample.
stop_time	Timestamp after last sample.
time_length	Length of signal in time units.

Methods

contains(t, /)	Whether time(s) are within the bounds of the signal.
dask_read(offset, n, /, **kwargs)	Read n samples from given offset using Dask arrays.
offset_at(t, /)	Returns nearest integer offset at given time.
read(offset, n, /, **kwargs)	Read n samples from given offset.
time_at(offset, /[, unit])	Returns time at given offset.

contains(t, /)

Whether time(s) are within the bounds of the signal.

dask_read(offset, n, /, **kwargs)

Read n samples from given offset using Dask arrays.

A convenience method equivalent to the read() method with use_dask=True.

Parameters

offsetint

Position to read from. Must be non-negative.

nint

Number of samples to read. Must be non-negative.

**kwargs

See read() for list of supported kwargs.

Returns

Signal

Signal of length n containing data that was read as a Dask array.

offset_at(t, /)

Returns nearest integer offset at given time.

Parameters

tQuantity or Time

Can be an absolute time as an astropy Time object, or an astropy Quantity in time units relative to the start.

Returns

int

The nearest integer position (in number of samples).

read(offset, n, /, **kwargs)

Read n samples from given offset.

Parameters

offsetint

Position to read from. Must be non-negative.

nint

Number of samples to read. Must be non-negative.

**kwargs

Currently supported keyword arguments:

• use_dask – Whether to use dask arrays.

• chunks – Chunk sizes if using dask arrays. By default, there is no chunking along the zeroth dimension.

Returns

Signal

Signal of length n containing data that was read.

time_at(offset, /, unit=None)

Returns time at given offset.

Parameters

offsetint

Position in number of samples.

unitUnit, optional

Desired unit of returned value (as an astropy unit). By default (None), the absolute timestamp is returned.

Returns

Quantity or Time

Time relative to the start as an astropy Quantity if unit is provided, otherwise an absolute time as an astropy Time object.