tot.rss {rMR}

Total Residual Sum of Squares for Broken Stick Model

Description

Calculates the total residual sum of squares for broken stick model (2 part)

Usage

tot.rss(data, break.pt, xvar, yvar)

Arguments

data

data frame for calculating total residual sum of squares.

break.pt

This is the data point at which the data are split for a broken stick model.

xvar

The x-variable in the data frame for broken stick model.

yvar

The y-variable in the data frame for broken stick model.

Value

The residual sum of squares of a broken stick model with a specified break point.

Author(s)

Tyler L. Moulton

See Also

codesumsq codeget.pcrit

Examples

## load data ##
data(fishMR)

## subset data to appropriate region ##

data<-fishMR[fishMR$DO.mgL < 4,] 
data$times <- data$times-min(data$times)
data<-data[data$times< 6800,]

## calculate total RSS for different breakpoints ##

a1 <- tot.rss(data, break.pt = 4000,
xvar = "times", yvar = "DO.mgL") 
a2 <- tot.rss(data, break.pt = 4250,
xvar = "times", yvar = "DO.mgL")
a3 <- tot.rss(data, break.pt = 4500,
xvar = "times", yvar = "DO.mgL")
a4 <- tot.rss(data, break.pt = 4750,
xvar = "times", yvar = "DO.mgL") 
a5 <- tot.rss(data, break.pt = 5000,
xvar = "times", yvar = "DO.mgL")
a6 <- tot.rss(data, break.pt = 5250,
xvar = "times", yvar = "DO.mgL")

# a5 represents the break point for the 
# best broken stick linear model of the
# above 6 options.