matrix, the matrix that results from soft-thresholding
norm
numeric, the norm of the matrix after soft-thresholding. This value is close to constraint if using the second option.
Arguments
x
matrix or Matrix, to be threshold.
gamma
numeric, the constraint of Lp norm, i.e. \(\|x\|\le \gamma\).
shrink
character(1), shrinkage method, either "soft"- (default) or "hard"-thresholding (see details).
epsilon
numeric, precision tolerance. This should be greater than .Machine$double.eps.
Details
A binary search to find the cut-off value.
shrink: The shrink option specifies the shrinkage operator to
use. Currently, there are two build-in options—“soft”- and
“hard”-thresholding. The “soft”-thresholding universally reduce all
elements and sets the small elements to zeros. The “hard”-thresholding
only sets the small elements to zeros.
References
Chen, F. and Rohe, K. (2020) "A New Basis for Sparse Principal Component Analysis."