R/yXm.R

In lmreg: Data and Functions Used in Linear Models and Regression with R: An Integrated Approach

yXm <- 
  function(response, treatments, blocks) {
	  n <- length(response)
	  treat <- unique(treatments)
	  ntreat <- length(treat)
	  block <- unique(blocks)
	  nblock <- length(block)
	  X <- NULL
	  y <- NULL
	  for (i in 1:ntreat) {
		  for (j in 1:nblock) {
			  yij <- response[treatments==treat[i]&blocks==block[j]]
			  y <- c(y,yij)
			  nij <- length(yij)
			  xij <- c(1, rep(0, (ntreat+nblock+ntreat*nblock)))
			  xij[1+i] <- 1
			  xij[1+ntreat+j] <- 1
			  xij[1+ntreat+nblock+((i-1)*nblock+j)] <- 1
			  X <- rbind(X, rep(1,nij)%*%t(xij))
		  }
	  }
	  return(list(y,X))
  }