smoothing: Smoothing Matrix in Nonsmooth NMF Models
Description
The function smoothing builds a smoothing matrix
for using in Nonsmooth NMF models.
Usage
smoothing(x, theta = x@theta, ...)
Arguments
x
a object of class NMFns.
theta
the smoothing parameter (numeric) between 0
and 1.
...
extra arguments to allow extension (not used)
Value
if x estimates a $r$-rank NMF, then the result
is a $r \times r$ square matrix.
Details
For a $r$-rank NMF, the smoothing matrix of parameter
$\theta$ is built as follows: $$S = (1-\theta)I +
\frac{\theta}{r} 11^T ,$$ where $I$ is the identity
matrix and $1$ is a vector of ones (cf.
NMFns-class for more details).