The `BOD`

data frame has 6 rows and 2 columns giving the
biochemical oxygen demand versus time in an evaluation of water
quality.

`BOD`

This data frame contains the following columns:

`Time`

A numeric vector giving the time of the measurement (days).

`demand`

A numeric vector giving the biochemical oxygen demand (mg/l).

# NOT RUN { require(stats) # simplest form of fitting a first-order model to these data fm1 <- nls(demand ~ A*(1-exp(-exp(lrc)*Time)), data = BOD, start = c(A = 20, lrc = log(.35))) coef(fm1) fm1 # using the plinear algorithm fm2 <- nls(demand ~ (1-exp(-exp(lrc)*Time)), data = BOD, start = c(lrc = log(.35)), algorithm = "plinear", trace = TRUE) # using a self-starting model fm3 <- nls(demand ~ SSasympOrig(Time, A, lrc), data = BOD) summary(fm3) # }