SSphilip {HydroMe} | R Documentation |
This selfstarting function estimates the infiltration parameters contained in the Philips model. It has an initial attribute that creates initial estimates of the parameters fc, and S
SSphilip(input, fc, S)
input |
A numeric vector of Time |
fc |
A numeric parameter representing the final steady infiltration capacity |
S |
a numeric parameter representing the slope of the infiltration characteristic curve at the early tmies of the infiltration process. It is the estimate of sorptivity at the supply moisture content |
a numeric vector of the same length as input. It is the value of the expression fc+(0.5*S)/sqrt(input) . It represents the fitted values by the Philips model
Omuto, Christian Thine
Philip, J.R., 1957 The theory of infiltration 4: Sorptivity and algebraic infiltration equations Soil Science 84, 257-264
SShort, SSGampt
##-- Use infiltration data data(infiltration) philip.nls <-nls(Rate~SSphilip(Time, fc, S), data=infiltration) plot(fitted(philip.nls)~infiltration$Rate) # Plot the fitted versus measured