nifty8.domains.structured_domain module

class StructuredDomain

Bases: Domain

The abstract base class for all structured domains.

An instance of a space contains information about the manifold’s geometry and enhances the functionality of Domain by methods that are needed for power spectrum analysis and smoothing.

property dvol

pixel volume(s)

Returns the volume factors of this domain, either as a floating point scalar (if the volume factors are all identical) or as a floating point array with a shape of self.shape.

Type:

float or numpy.ndarray(dtype=float)

get_fft_smoothing_kernel_function(sigma)

Helper for Gaussian smoothing.

This method, which is only implemented for harmonic domains, helps to smoothe fields that are defined on a domain that has this domain as its harmonic partner. The returned function does a pointwise evaluation of a zero-centered Gaussian on the field values, which corresponds to a convolution with a Gaussian kernel with sigma standard deviation in position space.

Parameters:

sigma (float) – A real number representing a physical scale on which the smoothing takes place. Mathematically sigma is the standard deviation of a convolution with a normalized, zero-centered Gaussian that takes place in position space.

Returns:

A smoothing operation that multiplies values with a Gaussian kernel.

Return type:

function (array-like -> array-like)

get_k_length_array()

k vector lengths, if applicable.

Returns the length of the k vector for every pixel. This method is only implemented for harmonic domains.

Returns:

An array containing the k vector lengths

Return type:

nifty8.field.Field

get_unique_k_lengths()

Sorted unique k-vector lengths, if applicable.

Returns an array of floats containing the unique k vector lengths for this domain. This method is only implemented for harmonic domains.

property harmonic

True iff this domain is a harmonic domain.

Type:

bool

property scalar_dvol

uniform pixel volume, if applicable

Returns the volume factors of this domain as a floating point scalar, if the volume factors are all identical, otherwise returns None.

Type:

float or None

property total_volume

Total domain volume.

Returns the sum over all the domain’s pixel volumes.

Type:

float