This class implements a simple wrapper strategy object that defines a unified interface to seeding methods, that are used to initialise NMF models before fitting them with any NMF algorithm.
(object="NMF", x="matrix", ...) and initialise
the NMF model object with suitable values for fitting the target
matrix x.
  
      signature(object = "NMFSeed"): Returns the workhorse function of the seeding method described by object.
  
      signature(object = "NMFSeed", value = "function"): Sets the workhorse function of the seeding method described by object.
  
      signature(key = "NMFSeed"): Creates an NMFSeed based on a template object (Constructor-Copy),
in particular it uses the same name.
  
      signature(object = "NMFSeed"): Show method for objects of class NMFSeed