| SSlbc {soilphysics} | R Documentation |
Self-Starting Nls Load Bearing Capacity Model
Description
A selfStart model that evaluates the Load Bearing Capacity
(Dias Jr., 1994) function and its gradient. It has an initial attribute
that creates initial estimates of the parameters b0 and b1.
Usage
SSlbc(theta, b0, b1) Arguments
theta |
a numeric vector of soil moisture values at which to evaluate the model. |
b0 |
a numeric parameter. |
b1 |
a numeric parameter. |
Value
a numeric vector with the same length of theta. It is the value of the
expression 10^{(b0 + b1 * \theta)}. Also, the gradient matrix with respect
to the parameters is attached as an attribute named gradient.
Author(s)
Anderson Rodrigo da Silva <anderson.agro@hotmail.com>
References
Dias Junior, M. S. (1994). Compression of three soils under longterm tillage and wheel traffic. 1994. 114p. Ph.D. Thesis - Michigan State University, East Lansing.
See Also
getInitiallbc, fitlbc, selfStart,
nls, sigmaP
Examples
data(compaction)
attach(compaction)
ss <- SSlbc(Mois, 2.79, -2.33)
ss[1:50] # prediction
PS # original data of preconsolidation stress
ss # prediction and gradient
# End (not run)