R/Cmip5Var2Stn.R

In PablitoCho/rSQM: Quantile Mapping Bias-correction at Station Level for Daily CMIP5 Data

#' Cmip5Var2Stn
#'
#' Read varialbe output files produced by Quantile mapping procedure and combine into station files
#'
#' @param stnid Weather station ID
#' @param varnms variable names
#' @param rcpnm RCP senario name
#' @param wdir  Working directory
#' @param mdlnm GCM model name
#'
#' @return data  station-based data which contains "year", "month", "yearmon", "date", "prcp", "tmax", "tmin", "wspd", "rhum", "rsds" column names
#' @export
#'
Cmip5Var2Stn <- function(stnid, varnms, rcpnm, wdir, mdlnm) {

#  setwd(wdir)
  nvar = length(varnms)
  #rcpname = c("historical", "rcp26", "rcp45", "rcp60", "rcp85")
  for (i in 1:nvar) {

    # User have to define RCP scenario : rcp[i]
    #rcpfile = paste(mdlnm,"_",rcpname[(rcpid+1)],"_",varnms[i],".csv",sep="")
    rcpfile = file.path(wdir, paste(mdlnm,"_",rcpnm,"_",varnms[i],".csv",sep=""))

    if(i==1) {

      if(file.exists(rcpfile)) {
        rcp_var1 = read.csv(rcpfile, header=T, na.strings = -99.00)
        coln = match(stnid, names(rcp_var1))
        nrows = length(rcp_var1[,1])
        rcpstn = rcp_var1[ ,c(1,coln)]
        colnames(rcpstn) = c("date", varnms[i])
        rcpstn$date = as.Date(rcpstn$date)
      } else {
        sdate = as.Date("1976-01-01")
        edate = as.Date("2100-12-31")
        dummydate = seq(sdate, edate, by=1)
        nrow = length(dummydate)
        dummyval = rep(-99.00, times=nrow)
        rcpstn = as.data.frame(cbind(dummydate, dummyval))
        colnames(rcpstn) = c("date", varnms[i])
        rcpstn$date = as.Date(dummydate)

      } # end of IF

    } else {

      if(file.exists(rcpfile)) {
        rcp_imsi = read.csv(rcpfile,header=T, na.strings = -99.00)
        coln = match(stnid, names(rcp_imsi))
        nrows = length(rcp_imsi[,1])
        rcp_imsi = rcp_imsi[ ,c(1,coln)]
        colnames(rcp_imsi) = c("date", varnms[i])
        rcp_imsi$date = as.Date(rcp_imsi$date)
        rcpstn = merge(rcpstn, rcp_imsi, by="date", all=T)
      } else {
        sdate = as.Date("1976-01-01")
        edate = as.Date("2100-12-31")
        dummydate = seq(sdate, edate, by=1)
        nrow = length(dummydate)
        dummyval = rep(-99.00, times=nrow)
        rcp_imsi = as.data.frame(cbind(dummydate, dummyval))
        colnames(rcp_imsi) = c("date", varnms[i])
        rcp_imsi$date = as.Date(dummydate)
        rcpstn = merge(rcpstn, rcp_imsi, by="date", all=T)
      } # end of IF
    } # end of IF
  } # varialbe LOOP

  rcpstn[is.na(rcpstn)] = -99.00

  data = FillDate(rcpstn)

  return(data)
}