R/bdiagMat.R

In metaSEM: Meta-Analysis using Structural Equation Modeling

bdiagMat <- function(x){
  if(!is.list(x)) stop("\"x\" must be a list.")
  n <- length(x)
  if(n==0) return(NULL)
  x <- lapply(x, function(y) if(length(y)) as.matrix(y) else stop("Zero-length component in x"))
  d <- array(unlist(lapply(x, dim)), c(2, n))
  rr <- d[1,]
  cc <- d[2,]
  rsum <- sum(rr)
  csum <- sum(cc)
  out <- array(0, c(rsum, csum))
  ind <- array(0, c(4, n))
  rcum <- cumsum(rr)
  ccum <- cumsum(cc)
  ind[1,-1] <- rcum[-n]
  ind[2,] <- rcum
  ind[3,-1] <- ccum[-n]
  ind[4,] <- ccum
  imat <- array(1:(rsum * csum), c(rsum, csum))
  iuse <- apply(ind, 2, function(y, imat) imat[(y[1]+1):y[2],
  (y[3]+1):y[4]], imat=imat)
  iuse <- as.vector(unlist(iuse))
  out[iuse] <- unlist(x)
  return(out)
}