R/tiseger.R

In maibrittbergh/dischanalyst: Analyses Hydrological Data, especially Discharge Data

#' Plot: Timeseries of mulitple Measurements
#'
#'@description Function plots timeseries within a certain timeframe. To provide clarity the function reduces the amount of displayed timeseries in case more than 20 stations cover the selected time frame. The plotted timeseries then are reduced to the representative timeseries within the timeframe. Besides the time it is also possible to adapt the resolution of the Y-axis. This guarantees the opportunity to compare rivers with the same mean discharge height.
#'
#' @param metadata "matrix" "array" ;  Metadata of grdc dataset. Can be created by \link[dischanalyst]{metadata_grdc} function.
#' @param data list; Contains all stations that the discharge analysis should consider. List can be created by \link[dischanalyst]{grdc_list}. Each entry of the list contains the existing discharge measurements (as numeric) and the corresponding dates (as character) for the station.
#' @param startyear integer; Latest possible startyear of timeseries. Minimum of xlim for plot.
#' @param endyear integer; Minimum endyear of timeseries. Maximum of xlim for plot.
#'@param frame1 minimum of Y-axis ( discharge/measurement value) -resolution.
#'@param frame2 maximum of Y-axis ( discharge/measurement value) - resolution.
#
#' @return geom_line plot. Every line represents one station.
#' @export
#' @import dplyr
#' @import ggplot2
#' @examples
#' \dontrun{
#' tiseger(metadata, "/Users/username/Desktop/folderone/datafolder/grdc_03_2021/grdc_disc/" , 1990,2020, metadata_repg= metadata_repg)
#' }
#'



tiseger=function(metadata, data, startyear, endyear,frame1, frame2){
  metadata_repg=metadata_repg(metadata)
  library(dplyr)
  l=nrow(metadata) #all stations, included in measurements
  stations_s=rep(F,l)
  stations_e=rep(F,l)
  for ( i in 1:l){
    stations_s[i]=metadata$startyear[i]<=startyear   #measurements at least as long as given timeseries
    stations_e[i]=metadata$endyear[i]>=endyear
  }

  start=which(stations_s == TRUE)
  end=which(stations_e == TRUE)
  l=length(start)
  vec=rep(F,l)
  for ( i in 1:l){
    if (identical(which(end==start[i]), integer(0))){
      vec[i]=F
    }else{ vec[i]=T}

  }
  timeseries=start[which(vec==T)]      #filtered. only stations with measurements during whole time included
  l=length(timeseries)
  stations=metadata$station[timeseries]
  rivernames=metadata$river[timeseries]

  ts=cbind(stations, rivernames)     #concluded in table
  lts=nrow(ts)

  if (lts > 20){
    nr= nrow(metadata_repg)
    g= rep(0,nr)

    for ( i in 1:nr){
      g[i]=is.element(metadata_repg$station[i], ts[,1])
    }
    true=which(g==1)
    ts_=metadata_repg$station[true]
    tr=metadata_repg$river[true]
    tsn=cbind(ts_, tr)
    ltsn=nrow(tsn)




    list2 =vector(mode = "list", length = ltsn)    # measurements added to table, new format: list
    names(list2)=ts_
    for ( i in 1:ltsn){

      val=data[[ts_[i]]]



      list2[[i]]=val




      hh=na.omit(bind_rows(list2, .id="station"))
      for ( i in 1:ltsn){
        number=which(hh$station== i)
        hh$station[number]=tsn[i,1]
      }


    }



  }else{


    list2 =vector(mode = "list", length = lts)    # measurements added to table, new format: list
    for ( i in 1:lts){


      val=data[[stations[i]]]



      list2[[i]]=val

      names(list2)=stations





      hh=na.omit(bind_rows(list2, .id="station"))
      for ( i in 1:lts){
        number=which(hh$station== i)
        hh$station[number]=ts[i,1]
      }

    }

  }




  title=paste("Timeseries of Discharge Values from", startyear, "to", endyear)
  graph= ggplot(hh, aes(x=YYYY.MM.DD, y=Value, colour=station))+geom_line()+ xlim(startyear,endyear)+ylim(frame1,frame2)+
    theme(legend.position="right", legend.box = "vertical")+ylab(expression('Discharge Value [m'^3*'/s]'))+xlab("Time [years]")+
    labs(title=title)







  return(graph)
}