##Collates 2011 CRUTEM data

#http://www.metoffice.gov.uk/research/climate/climate-monitoring/land-and-atmosphere/surface-station-records

##COLLATION FUNCTIONS
###########################

##function to read information on 5113 stations
get.info=function() {
	loc="http://www.cru.uea.ac.uk/cru/data/temperature/station-data/headers.txt"
	download.file(loc,"temp")
	class0=rep("numeric",10);class0[c(1,5,6)]="character"
	x= read.fwf("temp",widths=c(6,4,5,6,21,14,4,4,4,4),colClasses=class0,fill=TRUE)
	names(x)=c("id","lat","long","alt","name","country","start","end","code","code1")
	x$id=trim(x$id)
	n=nchar(x$id);
	temp= substr(x$id,1,1)==" " ; x$id[temp]=paste("0",substr(x$id[temp],2,6),sep="")
	x=x[!is.na(x$id),]
	x$name=trim(x$name); x$country=trim(x$country) 
	x$lat=x$lat/10;x$long=x$long/10; x$long= -x$long
	x$name= gsub("-+$","",x$name)
	x$country= gsub("-+$","",x$country)
	x$alt[x$alt ==-999]=NA
	return(x)
}


#function to make time series from individual station
getcru=function(filename="01/010010") {	
	handle=unz("temp.zip",filename)
	fred=scan(handle,what="",sep="\n")
	close(handle)
	m= grep("Obs.",fred)
	if(length(m)==0) return(NA) else {
	fred=fred[(m+1):length(fred)]
	writeLines(fred,"temp")
	test=read.table("temp")
	test[test==-99.0]=NA
	N=nrow(test)
	if(test[N,1]-test[1,1]+1 == N) getcru=ts( c(t(test[,2:13])),freq=12,start=test[1,1]) 
	return(getcru)}
}
  ## station=getcru(filename="01/010010") #example

#collate into list from HAD version
make.cru=function(Info=info) {
	download.file("http://www.metoffice.gov.uk/media/zip/e/0/station_files.20110720.zip","temp.zip",mode="wb")
	K=nrow(Info)
	cru= rep(list(NA),K) ;names(cru)=Info$id
	for (i in (1:K) { 
          loc= paste(substr(Info$id[i],1,2),"/",Info$id[i],sep="")
	  cru[[i]]=getcru(loc)
	}
	return(cru)
}


	info=get.info()
	cru=make.cru()
	info$length=unlist(sapply(cru,length))
	info$length[info$length==1]=0
	# save(info,file="d:/climate/data/station/cru/2011/info.tab")
		#www.climateaudit.info/data/station/cru/2011/info.tab

	# save(cru,file="d:/climate/data/station/cru/2011/cru.tab")
	  	#www.climateaudit.info/data/station/cru/2011/cru.tab