seedwater (version 2.0)

soakingmodels: Modeling Seed Soaking Kinetics

Description

An interactive function to fit nonlinear models for seed soaking kinetics.

Usage

soakingmodels(moisture, time)

Arguments

moisture

a numeric vector containing values of seed water content or weight of seed sample. See Details.

time

a numeric vector containing values of soaking time.

Value

An object of class nls containing the parameter estimates.

Side Effects

An interactive graphic is displayed for selecting the model and the initial values for the parameters.

Details

soakingmodels is set to fit curves of water absorption (WA%) rather than moisture. It is automatically calculated through the equation:

$$ WA = \frac{\code{moisture} - Mi}{Mi} $$

where \(Mi\) is the initial value of seed moisture.

These are the currently available models:

(Peleg) \( WA = x/(k1 + k2 * x) \)

(Logistic) \( WA = a/(1 + exp(-b1 * (x - c1))) \)

(Logistic adapted) \( WA = a/(1 + exp(-b1 * (x - c1))) + exp(b2 * (x - c2)) \)

(Peleg adapted) \( WA = x/(k1 + k2 * x) + exp(b2 * (x - c2)) \)

where \(x\) represents time and \(a\), \(k1\), \(k2\), \(b1\), \(b2\), \(c1\) and \(c2\) are the model parameters. Check da Silva et al. (2018) for more details and description of parameters.

References

da Silva, A. R. et al. (2018) Modeling the Three Phases of the Soaking Kinetics of Seeds. Agronomy Journal, 110:164-170. doi:10.2134/agronj2017.07.0373

See Also

nls, dryingmodels

Examples

# NOT RUN {
data(onionseeds)
if (interactive()) {
   res <- with(onionseeds, soakingmodels(moisture = Weight, time = Time))
   summary(res)
}

# End (not run)
# }