nlraa (version 1.9.7)

SSscard3: self start for smooth cardinal temperature response

Description

Self starter for smooth cardinal temperature response function

Usage

scard3(x, tb, to, tm, curve = 2)
SSscard3(x, tb, to, tm, curve = 2)

Value

scard3: vector of the same length as x using a scard3 function

Arguments

x

input vector (x) which is normally ‘temperature’.

tb

base temperature

to

optimum temperature

tm

maximum temperature

curve

curvature (default is 2)

Author

Caio dos Santos and Fernando Miguez

Details

An example application can be found in (doi:10.1016/j.envsoft.2014.04.009)

This function is described in Archontoulis and Miguez (2015) - (doi:10.2134/agronj2012.0506) - Equation 5.1 in Table 1.

Examples

# \donttest{
## A temperature response function
require(ggplot2)
set.seed(1234)
x <- 1:50
y <- scard3(x, 13, 25, 36) + rnorm(length(x), sd = 0.05)
dat1 <- data.frame(x = x, y = y)
fit1 <- nls(y ~ SSscard3(x, tb, to, tm), data = dat1)

ggplot(data = dat1, aes(x, y)) + 
  geom_point() + 
  geom_line(aes(y = fitted(fit1)))
# }