FOMT {chemdeg}R Documentation

First-Order Multi-Target model regression

Description

The function performs a non-linear regression using the first-order multi-target model. The model equation is:

SS0=1(1ekt)m\frac{S}{S_0}=1-(1-e^{-k\,t})^m

where S/S0S/S_0 is the fraction of surviving molecules, kk is the average number of hits per time unit, mm is the number of hits required to degrade the molecule, and tt is time.

Usage

FOMT(dtframe)

Arguments

dtframe

A data-frame containing 2 or 3 columns: time, normalized concentration and error (optional), respectively

Details

The FOMT model has been proposed as an alternative to the Weibull equation that is commonly used when the time-dependent behavior of the data significantly deviates from that predicted by standard chemical models.

Value

Returns the results of the regression as a nls object.

See Also

FOMTm(), par_est_FOMT()

Examples

t <- c(0, 4, 8, 12, 16, 20)
conc <- c(1, 0.98, 0.99, 0.67, 0.12, 0.03)
err <- c(0.02, 0.05, 0.04, 0.04, 0.03, 0.02)
dframe <- data.frame(t, conc, err)
FOMT <- FOMT(dframe)
plot(dframe[[1]], dframe[[2]])
arrows(dframe[[1]], dframe[[2]] + dframe[[3]],
  dframe[[1]], dframe[[2]] - dframe[[3]],
  length = 0
)
newt <- seq(0, 21, by = 0.1)
lines(newt, predict(FOMT, newdata = list(t = newt)))

dframe1 <- data.frame(t, conc)
FOMT1 <- FOMT(dframe1)
plot(dframe1[[1]], dframe1[[2]])
lines(newt, predict(FOMT1, newdata = list(t = newt)))
summary(FOMT)
summary(FOMT1)

[Package chemdeg version 0.1.4 Index]