Helper Functions#

Configuration Functions#

Function Name

Description

run_config()

Generates and caches all precomputed arrays.

Statistics Functions#

Function Name

Description

compute_mean_variance()

Computes the mean and variance of spherical harmonic coefficients \(f_{\ell m}\).

normalize_map()

Normalises a spherical map to zero mean and unit variance.

compute_C01_and_C11()

Stand alone function to compute the fourth and sixth order covariance statistics.

add_to_S1()

Computes and appends the mean field statistic \(\text{S1}_j = \langle |\Psi^\lambda f| \rangle\) at scale \(j\).

add_to_P00()

Computes and appends the second order power statistic \(\text{P00}_j = \langle |\Psi^\lambda f|^2 \rangle\) at scale \(j\).

add_to_C01()

Computes and appends the fourth order covariance statistic \(\text{C01}_j = \text{Cov}\big [ \Psi^{\lambda_1} f, \Psi^{\lambda_1} | \Psi^{\lambda_2} f | \big ]\) at scale \(j\).

add_to_C11()

Computes and appends the sixth order covariance statistic \(\text{C11}_j = \text{Cov}\big [ \Psi^{\lambda_1} | \Psi^{\lambda_3} f |, \Psi^{\lambda_1} | \Psi^{\lambda_2} f | \big ]\) at scale \(j\).

Statistical Normalisation Functions#

Function Name

Description

compute_norm()

Computes normalisation for the scattering covariance statistics.

apply_norm()

Applies normalisation to a complete list of covariance statistics.

Reindexing Functions#

Function Name

Description

nested_list_to_list_of_arrays()

Specific reindexing function which switches covariance wavelet scale list ordering.

list_to_array()

Converts list of covariance statistics to array of statistics for e.g. Loss functions.