R/read.rdf.R

In rabutler/RWDataPlot: Read, manipulate, and plot data from RiverWareTM (riverware.org), that is saved as rdf (RiverWare data format) files

# Written by Cameron Bracken - circa 2010

read_rdf_header <- function(con,end){
	
	#assumes connection is already correctly positioned
	
	obj <- list()
	
	repeat{
		line <- readLines(con,n=1)
		if(line == end) break

		splitLine <- strsplit(line,':')[[1]]
		name <- splitLine[1]
		if(length(splitLine) > 1){
			if(substr(splitLine[2],1,1) == ' ')
				splitLine[2] <- substr(splitLine[2],2,nchar(splitLine[2]))
			contents <- paste(splitLine[2:length(splitLine)],collapse=':')
		} else{
			contents <- NA
		}
		obj[[name]] <- contents
		
		if(end == 1) break
		
	}
	
	#returns the object, but connection is advanced
	return(obj)
	
}
	
read_rdf_meta <- function(rdf.con,rdf.obj){
	
	rdf.obj[['meta']] <- read_rdf_header(rdf.con,'END_PACKAGE_PREAMBLE')
	return(rdf.obj)
	
}

read_next_line_and_rewind <- function(con){
	
	str <- readLines(con,n=1)
	seek(con,seek(con)-nchar(str)-2)
	return(str)
	
}

read_rdf_run <- function(rdf.con,rdf.obj){
	
	this.run <- length(rdf.obj$runs) + 1
	rdf.obj$runs[[this.run]] <- read_rdf_header(rdf.con,'END_RUN_PREAMBLE')
	
		#time steps
	nts <- as.integer(rdf.obj$runs[[this.run]]$time_steps)
		#for non-mrm files
	if(length(nts) == 0) 
		nts <- as.integer(rdf.obj$runs[[this.run]]$timesteps)
		
	rdf.obj$runs[[this.run]][['times']] <- readLines(rdf.con,n=nts)
	
		#Series
	nob <- 0
	repeat{
		
		nob <- nob + 1
		rdf.obj$runs[[this.run]][['objects']][[nob]] <- read_rdf_header(rdf.con,'END_SLOT_PREAMBLE')
		
			#name the objecst after their object.slot name
		obj.name <- rdf.obj$runs[[this.run]][['objects']][[nob]]$object_name
		slot.name <- rdf.obj$runs[[this.run]][['objects']][[nob]]$slot_name
		name <- paste(obj.name,slot.name,sep='.')
		names(rdf.obj$runs[[this.run]][['objects']])[nob] <- name
		
			#read in the extr two header pieces
		rdf.obj$runs[[this.run]][['objects']][[nob]]$units <- read_rdf_header(rdf.con,1)[[1]]
		rdf.obj$runs[[this.run]][['objects']][[nob]]$scale <- read_rdf_header(rdf.con,1)[[1]]

		rdf.obj$runs[[this.run]][['objects']][[nob]]$values <- as.numeric(readLines(rdf.con,n=nts))
		
			#END_COLUMN,END_SLOT, table slots need support here
		dummy <- readLines(rdf.con,n=2)
		
		if(read_next_line_and_rewind(rdf.con) == 'END_RUN'){
			dummy <- readLines(rdf.con,n=1)
			break
		}
	}
	return(rdf.obj)
	
}

#' Read an rdf file into R.
#' 
#' \code{read.rdf} reads an rdf file into R and formats it as a multi-level list containing
#' all of the metadata included in the rdf file.  Rdf files are generated by RiverWare
#' and are documented in the \href{http://riverware.org/PDF/RiverWare/documentation/}{RiverWare documentation}.
#' 
#' @param file The input rdf file that will be read into R.
#' @return A multi-level list containing all metadata and slot data in the original rdf file.
#' @examples
#' zz <- read.rdf(system.file('extdata/Scenario/DNF,CT,IG', "KeySlots.rdf", package = "RWDataPlot"))
#' 
#' @export

read.rdf <- function(file){
	
	rdf.obj <- list()
	rdf.con <- file(file,'r')
	
	rdf.obj <- read_rdf_meta(rdf.con,rdf.obj)
	for(i in 1:as.numeric(rdf.obj$meta$number_of_runs))
		rdf.obj <- read_rdf_run(rdf.con,rdf.obj)
	
	close(rdf.con)
	
	return(rdf.obj)
}