moinput: Model Operations Input Data Library

#' @importFrom reshape2 melt
#' @importFrom readxl read_excel

readPopulationTWN<- function(subtype) {
  files <- c(medium="A1. Population Projections - Medium Variant.xlsx",
             high="A2. Population Projections  - High Variant.xlsx",
             low="A3. Population Projections  - Low Variant.xlsx")
  
  file <- toolSubtypeSelect(subtype,files)
  
  twn <- as.data.frame(suppressMessages(read_excel(file,sheet="M3",skip=1)))
  twn <- twn[!is.na(twn[[2]]),]
    
  names(twn)[3] <- paste(names(twn)[2],twn[1,3],sep="_")
  names(twn)[4] <- paste(names(twn)[2],twn[1,4],sep="_")
  names(twn)[2] <- paste(names(twn)[2],twn[1,2],sep="_")
  names(twn)[6] <- paste(names(twn)[5],twn[1,6],sep="_")
  names(twn)[7] <- paste(names(twn)[5],twn[1,7],sep="_")
  names(twn)[5] <- paste(names(twn)[5],twn[1,5],sep="_")
  names(twn)[9] <- paste(names(twn)[8],twn[1,9],sep="_")
  names(twn)[10] <- paste(names(twn)[8],twn[1,10],sep="_")
  names(twn)[8] <- paste(names(twn)[8],twn[1,8],sep="_")
  
  twn <- twn[-1,]
  twn <- suppressMessages(melt(twn,id.vars="Year"))
  twn$value <- as.numeric(twn$value)
  twn$variable <- gsub(" +","_",twn$variable)
  twn$variable <- gsub("_years"," years",twn$variable,fixed = TRUE)
  
    
  x <- as.magpie(twn)
  return(x)
}