ldf(object, type)
# S3 method for flash
ldf(object, type = "f")
# S3 method for flash_fit
ldf(object, type = "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).
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)
.
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.