f.linear.plateau {FertBoot} | R Documentation |
Fitting linear plateau model using multiple initial values
Description
f.linear.plateau
fits linear plateau model using multiple initial values. The multiple initial values are randomly sampled in a "cube" of parameter space.
More precisely, linear plateau model assumes y ~ a + b * (x - c) * (x <= c).
Usage
f.linear.plateau(
d,
start = list(a = 1, b = 1, c = 1),
plus_minus = 100,
n.start = 1000,
msg = FALSE
)
Arguments
d |
data frame with two columns ( |
start |
initial estimate for non-linear least square (default value: |
plus_minus |
radius of random initial values (default: |
n.start |
total number of initial points considered (default: |
msg |
logical flag whether printing progress |
Value
f.linear.plateau
returns a list of two components (if converged): nls.summary
: summary of the fitted model; nls.model
: nls object
Examples
set.seed(4)
x <- rep(1:300, each=4)
a <- 8; b <- 0.05; c <- 100
y <- a + b * (x - c) * (x <= c) +
rnorm(length(x), sd=0.1)
d <- cbind(x,y)
# a converged example:
ans <- f.linear.plateau(d, start=list(a = 7, b = 0.1, c = 150),
plus_minus=10, n.start=10, msg=FALSE)
summary(ans$nls.model)
[Package FertBoot version 0.5.0 Index]