qiu_signals.integer_axis

Uniformly sampled axes of integer indices.

Classes:

• IndexOrdering –

  Orderings of the integer indices of the samples of an axis.

• IntegerAxis –

  A uniformly sampled axis of integer indices.

IndexOrdering

Bases: ExtendedEnum

Orderings of the integer indices of the samples of an axis.

For an axis of N samples, the sample at array position k gets the index:

• NATURAL: k, i.e. 0, 1, ..., N-1.
• FFT: the ordering of numpy.fft.fftfreq, i.e. the non-negative indices 0, 1, ..., ceil(N/2)-1 followed by the negative ones -floor(N/2), ..., -1.
• CENTERED: the FFT ordering after numpy.fft.fftshift, i.e. the ascending indices -floor(N/2), ..., ceil(N/2)-1.

Attributes:

• NATURAL –
• FFT –
• CENTERED –

NATURAL class-attribute instance-attribute

NATURAL = 'natural'

FFT class-attribute instance-attribute

FFT = 'fft'

CENTERED class-attribute instance-attribute

CENTERED = 'centered'

IntegerAxis

IntegerAxis(size: int, ordering: IndexOrdering)

A uniformly sampled axis of integer indices.

The sample at array position k has the integer index index[k], given by the ordering of the axis.

Parameters:

• size (int) –

  Number of samples, at least 1.

• ordering (IndexOrdering) –

  Ordering of the integer indices of the samples.

Raises:

• ValueError –

  If the size is smaller than 1.

Attributes:

• size (int) –

  Number of samples.

• ordering (IndexOrdering) –

  Ordering of the integer indices of the samples.

• index (NDArray[int_]) –

  Return the integer indices of the samples according to the ordering.

Source code in packages/qiu-signals/src/qiu_signals/integer_axis.py

def __init__(self, size: int, ordering: IndexOrdering) -> None:
    """Initialize an integer axis.

    Args:
        size: Number of samples, at least 1.
        ordering: Ordering of the integer indices of the samples.

    Raises:
        ValueError: If the size is smaller than 1.
    """
    if size < 1:
        raise ValueError(f"The size must be at least 1, got {size}.")

    self.size = size
    self.ordering = IndexOrdering(ordering)

size instance-attribute

size: int = size

Number of samples.

ordering instance-attribute

ordering: IndexOrdering = IndexOrdering(ordering)

Ordering of the integer indices of the samples.

index property

index: NDArray[int_]

Return the integer indices of the samples according to the ordering.