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.