R/get.W.R

In dmt: Dependency Modeling Toolkit

# (C) 2008-2011 Leo Lahti and Olli-Pekka Huovilainen          
# All rights reserved. 
# FreeBSD License (keep this notice)     


# "Reality is merely an illusion, albeit a very persistent one."
# - Albert Einstein
        
	
get.W <- function (vec, Dim) {

  # (C) 2008-2011 Leo Lahti and Olli-Pekka Huovilainen          
  # All rights reserved. 
  # FreeBSD License (keep this notice)     

  # Convert parameter vector into matrices Wx and Wy
  W <- list()
  W$X <- array(vec[1:(Dim$X*Dim$Z)], dim = c(Dim$X,Dim$Z))
  T <- array(vec[-seq(Dim$X*Dim$Z)], dim = c(Dim$Y,Dim$X))
  W$Y <- T%*%W$X

  list(W = W, T = T)
}


get.W.nonneg <- function (vec, Dim) {

  # (C) 2008-2011 Leo Lahti and Olli-Pekka Huovilainen          
  # All rights reserved. 
  # FreeBSD License (keep this notice)     

  # Convert parameter vector into matrices Wx and Wy
  # in general Wx != Wy

  # Note that we always assume that W is positive Therefore remove the
  #sign here to speed up optimization
  vec <- abs(vec)
  
  # NOTE: assumes dx = dy  
  W <- list()
  nx <- Dim$X*Dim$Z
  W$X <- array(vec[1:nx], dim = c(Dim$X, Dim$Z))
  W$Y <- array(vec[(nx + 1):length(vec)], dim = c(Dim$Y, Dim$Z))
  W$total <- rbind(W$X, W$Y)
  
  W

}

get.W.nonneg.identical <- function (vec, Dim) {  

  # (C) 2008-2011 Leo Lahti and Olli-Pekka Huovilainen          
  # All rights reserved. 
  # FreeBSD License (keep this notice)     

  # Convert parameter vector into matrix               
  # Note that we always assume that W is positive          
  # Therefore remove the sign here to speed up optimization    
  
  array(abs(vec), dim = c(Dim$X, Dim$Z))              
  
}