Simple exponential functions

Description

First order exponential decrease (exp1) or increase (exp2). These are equations 1.1 and 1.2 in Table 1 in the paper referenced below.

Usage

1
exp1(time, Yo, rate)

Arguments

time

a numeric vector of values at which to evaluate the model.

Yo

a numeric parameter representing the asymptote.

rate

rate of decrease

Value

a numeric vector of length equal to the inputs

Author(s)

Fernando E. Miguez

References

Nonlinear Regression Models and Applications in Agricultural Research. Sotirios V. Archontoulis and Fernando E. Miguez. Agronomy Journal. doi: 10.2134/agronj2012.0506

Examples

1
2
3
4
5
6
7
8
9
require(lattice)
## Set parameter values and plot the relationship
time <- seq(0, 100,5)
ans1 <- exp1(time, Yo=1, rate=0.01)
ans2 <- exp1(time, Yo=1, rate=0.05)
ans3 <- exp1(time, Yo=1, rate=-0.01)

xyplot(ans1 + ans2 + ans3 ~ time, type="l", auto.key=TRUE,
       ylab = "OM decomposition", xlab = "time")