fitlbc: Parameter Estimation of the Load Bearing Capacity Model

Description Usage Arguments Value Author(s) References See Also Examples

Description

This function creates initial parameter estimates of the nonlinear Load Bearing Capacity (Dias Jr., 1994) model, i.e., σ_P = 10 ^ {(b0 + b1 * θ)}, by using two methods: a getInitial method or a log-linearization. Then, it uses them to provide its least-squares estimates via nls.

Usage

1
 fitlbc(theta, sigmaP, ...) 

Arguments

theta

a numeric vector containing soil moisture values.

sigmaP

a numeric vector containing values of soil preconsolidation stress.

...

further arguments to nls.

Value

A nls object.

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

sigmaP, fitbusscher, maxcurv, Rsq

Examples

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data(compaction)
attach(compaction)
out <- fitlbc(theta = Mois, sigmaP = PS)
summary(out)
Rsq(out)
curve(10^(coef(out)[1] + coef(out)[2]*x))

# End (not run)


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