pca_expand.py

#!/usr/bin/env python3
# License: GPLv3
# Portions of this code refactored from Matlab to Python using Jetbrains AI Assistant, then reviewed and corrected by human.
# Original authors:
#   P.Antonelli
#   L.Borg
#   R.Garcia

import numpy as np
from functools import reduce
        
def dimprod(shp):
    return reduce(lambda a,b: a * b, shp)

def pca_expand( M: np.ndarray, U: np.ndarray, coef: np.ndarray ) -> np.ndarray:
    ntr = coef.shape[-1]
    shp = coef.shape[:-1]
    nX = dimprod(shp)
    coef = coef.reshape((nX, ntr))
    # PCM = np.tile(M, (1, nX))
    col = np.dot(coef, U[:ntr,:]) + M
    # print(col.shape)
    # print(M.shape)
    nrecon = col.shape[-1]
    return col.reshape(tuple(shp) + (nrecon,))