| SSsharp {nlraa} | R Documentation |
self start for temperature response
Description
Self starter for temperature response function
Usage
sharp(temp, r_tref, e, el, tl, eh, th, tref = 25)
SSsharp(temp, r_tref, e, el, tl, eh, th, tref = 25)
Arguments
temp |
input vector (x) which is normally ‘temperature’. |
r_tref |
rate at the standardised temperature, tref |
e |
activation energy (eV) |
el |
low temperature de-activation energy (eV) |
tl |
temperature at which the enzyme is half active and half suppressed due to low temperatures |
eh |
high temperature de-activation energy (eV) |
th |
temperature at which enzyme is half active and half suppressed dut to high temperatures |
tref |
standardisation temperature in degrees centigrade. Temperature at which rates are not inactivated by either high or low temperatures. Typically, 25 degrees. |
Details
For details see Schoolfield, R. M., Sharpe, P. J. & Magnuson, C. E. Non-linear regression of biological temperature-dependent rate models based on absolute reaction-rate theory. Journal of Theoretical Biology 88, 719-731 (1981)
Value
sharp: vector of the same length as x using a sharp function
Note
I do not recommend using this function.
Examples
require(ggplot2)
require(minpack.lm)
temp <- 0:45
rate <- sharp(temp, 1, 0.03, 1.44, 28, 19, 44) + rnorm(length(temp), 0, 0.05)
dat <- data.frame(temp = temp, rate = rate)
## Fit model
fit <- nlsLM(rate ~ SSsharp(temp, r_tref, e, el, tl, eh, th, tref = 20), data = dat)
## Visualize
ggplot(data = dat, aes(temp, rate)) + geom_point() + geom_line(aes(y = fitted(fit)))