R/generalize.hz.R

In aqp: Algorithms for Quantitative Pedology

# return a vector of generalized horizon names, based on:
# a vector of new names
# a vector of patterns
# code for any non-matching hz designations
generalize.hz <- function(x, new, pat, non.matching.code='not-used') {
	
	# init vector of 'other', same length as original horizon name vector
	g <- rep(non.matching.code, times=length(x))
	
	# iterate over new new names, match with patterns, assign new hz names
	for(i in seq_along(new)) {
		g[grep(pat[i], x)] <- new[i]
	}
	# convert to factor, and re-level
	g <- factor(g, levels=c(new, non.matching.code))
	return(g)
}


# convert a cross-tabulation: {original, genhz} to adjacency matrix
genhzTableToAdjMat <- function(tab) {
  tab <- as.matrix(tab)
  # extract unique set of names
  nm <- sort(unique(unlist(dimnames(tab))))
  # generate full matrix with named dimensions
  m <- matrix(nrow=length(nm), ncol=length(nm), data=0)
  dimnames(m) <- list(nm, nm)
  # set adjacency information via sub-matrix containing the original cross-tab
  m[rownames(tab), colnames(tab)] <- tab
  return(m)
}