EGRET (version 2.3.0)

runSurvReg: Run the weighted survival regression for a set of estimation points (defined by DecYear and Log(Q))

Description

This function runs the survival regression which is the concentration estimation method of WRTDS. It uses sample data from the data frame Sample. It does the estimation for a set of data points defined by two vectors: estPtYear and estPtLQ. It returns an array of results for the estimation points. The array returned contains yHat, SE and ConcHat (in that order).

Usage

runSurvReg(estPtYear, estPtLQ, numDays, DecLow, DecHigh, Sample, windowY = 7,
  windowQ = 2, windowS = 0.5, minNumObs = 100, minNumUncen = 50,
  interactive = TRUE, edgeAdjust = TRUE)

Arguments

estPtYear

numeric vector of Decimal Year values at the estimation points

estPtLQ

numeric vector of ln(Q) values at the estimation points, must be the same length as estPtYear

numDays

number of days in the Daily record

DecLow

number specifying minimum decimal year

DecHigh

number specifying maximum decimal year

Sample

dataframe created for EGRET analysis

windowY

numeric specifying the half-window width in the time dimension, in units of years, default is 7

windowQ

numeric specifying the half-window width in the discharge dimension, units are natural log units, default is 2

windowS

numeric specifying the half-window with in the seasonal dimension, in units of years, default is 0.5

minNumObs

numeric specifying the miniumum number of observations required to run the weighted regression, default is 100

minNumUncen

numeric specifying the minimum number of uncensored observations to run the weighted regression, default is 50

interactive

logical specifying whether or not to display progress message

edgeAdjust

logical specifying whether to use the modified method for calculating the windows at the edge of the record. The modified method tends to reduce curvature near the start and end of record. Default is TRUE.

Value

• resultSurvReg numeric array containing the yHat, SE, and ConcHat values array dimensions are (numEstPts,3)

Examples

eList <- Choptank_eList
estPtYear<-c(2001.0,2005.0,2009.0)
estPtLQ<-c(1,1,1)
Sample <- getSample(eList)
numDays <- Sample$Julian[nrow(Sample)] - Sample$Julian[1] + 1
DecLow <- Sample$DecYear[1]
DecHigh <- Sample$DecYear[nrow(Sample)]
resultSurvReg <- runSurvReg(estPtYear,estPtLQ,numDays,DecLow,DecHigh,Sample)