SSscard3 {nlraa}

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)

Arguments

x

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

tb

base temperature

to

optimum temperature

tm

maximum temperature

curve

curvature (default is 2)

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.

Value

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

Author(s)

Caio dos Santos and Fernando Miguez

Examples

## 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)))