Given a flash or flash_fit object, returns the LDF
decomposition \(Y \approx LDF'\).
ldf(object, type)# S3 method for flash
ldf(object, type = "f")
# S3 method for flash_fit
ldf(object, type = "f")
A list with fields L, D, and F, each of which
corresponds to one of the matrices in the decomposition \(Y \approx LDF'\)
(with the columns of \(L\) and \(F\) scaled according to
argument type). Note that D is returned as a vector rather
than a matrix (the vector of diagonal entries in \(D\)). Thus, "fitted
values" \(LDF'\) can be recovered as L %*% diag(D) %*% t(F).
An object inheriting from class flash or
flash_fit.
Takes identical arguments to function norm. Use
"f" or "2" for the 2-norm (Euclidean norm); "o" or
"1" for the 1-norm (taxicab norm); and "i" or "m" for
the infinity norm (maximum norm).
ldf(flash): LDF decomposition for flash objects
ldf(flash_fit): LDF decomposition for flash_fit objects
When the prior families \(G_\ell^{(k)}\) and \(G_f^{(k)}\) are closed
under scaling (as is typically the case), then the EBMF model (as
described in the documention to function flash) is only
identifiable up to scaling by a diagonal matrix \(D\):
$$Y = LDF' + E.$$
Method ldf scales columns \(\ell_k\) and \(f_k\)
so that, depending on the argument to parameter type, their
1-norms, 2-norms, or infinity norms are equal to 1.