R/plot1of15.R

In USGS-R/EGRET: Exploration and Graphics for RivEr Trends

#' plots 1 of the 15 graphs of streamflow statistics on a single page
#'
#' Part of the flowHistory system.  It is designed to create each of the component graphs for the function \code{\link{plot15}}. The 15 graphs include annual and four seasonal graphs
#' for each of 3 flow statistics: 1-day maximum, mean, and 7-day minimum.
#' The computations involved are the same as the ones used in \code{\link{plotFlowSingle}} or in \code{\link{makeAnnualSeries}}
#' @param yearStart A numeric value for the year in which the graph should start
#' @param yearEnd A numeric value for the year in which the graph should end
#' @param qf a scale factor to convert discharge in cubic feet per second to mm/day, it is 86 / (drainage area in square kilometers)
#' @param istat A numeric value selecting the flow statistic to be plotted, must be an integer from 1 to 8
#' @param eList named list with at least the Daily and INFO dataframes
#' @param isBottom logical, if TRUE the graph is from the bottom row and thus needs x axis labels, if FALSE it does not need labels
#' @keywords graphics streamflow
#' @export
#' @examples
#' eList <- Choptank_eList
#' plot1of15(eList, 1980, 2010, 0.2938476, 5)
plot1of15<-function(eList, yearStart, yearEnd, qf, istat,
                    isBottom=FALSE) {
  
  localINFO <- getInfo(eList)
  
  if("edgeAdjust" %in% names(localINFO)){
    edgeAdjust <- localINFO$edgeAdjust
  } else {
    edgeAdjust <- TRUE
  }
  
  localAnnualSeries <- makeAnnualSeries(eList, edgeAdjust = edgeAdjust)
  
  xSpan<-c(yearStart,yearEnd)
  xTicks<-pretty(xSpan,n=6)
  numXTicks<-length(xTicks)
  xLeft<-xTicks[1]
  xRight<-xTicks[numXTicks]
  x<-localAnnualSeries[1,istat,]
  y<-qf*localAnnualSeries[2,istat,]
  yTop<-1.05*max(y,na.rm=TRUE)
  yTicks<-yPretty(yTop)
  numYTicks<-length(yTicks)
  yTop<-yTicks[numYTicks]
  plot(x,y,axes=FALSE,xlim=c(xLeft,xRight),xaxs="i",ylim=c(0,yTop),yaxs="i",ylab="",xlab="",main="",type="p")
  if(isBottom) axis(1,tcl=0.5,at=xTicks,labels=xTicks) else axis(1,tcl=0.5,at=xTicks,labels=FALSE)
  axis(2,tcl=0.5,at=yTicks,labels=TRUE)
  axis(3,tcl=0.5,at=xTicks,labels=FALSE)
  axis(4,tcl=0.5,at=yTicks,labels=FALSE)
  y<-qf*localAnnualSeries[3,istat,]
  par(new=TRUE)
  plot(x,y,axes=FALSE,xlim=c(xLeft,xRight),xaxs="i",ylim=c(0,yTop),yaxs="i",ylab="",xlab="",main="",type="l")
  axis(1,tcl=0.5,at=xTicks,labels=FALSE)
  axis(2,tcl=0.5,at=yTicks,labels=FALSE)
  axis(3,tcl=0.5,at=xTicks,labels=FALSE)
  axis(4,tcl=0.5,at=yTicks,labels=FALSE)
  box()
}