kostiakov: Kostiakov infiltration parameter optmisation in R

In gowusu/vadose: The estimation of saturated hydraulic conductivity and soil water retention Curves in the vadose zone

Description

This function optimises Kostiakov (1932) cumulative infiltration (I) parameters.

Usage

kostiakov(data = NULL, time, I, a = 0.1, k = 0.1, group = NULL)

## Default S3 method:
kostiakov(data = NULL, time, I, a = 0.1, k = 0.1,
  group = NULL)

## S3 method for class 'kostiakov'
predict(object, time = NULL, ...)

## S3 method for class 'kostiakov'
plot(x, xlab = "Time(Minutes)",
  ylab = "Cumulative (cm)", main = NULL, layout = NULL, ...)

## S3 method for class 'kostiakov'
summary(object, ...)

Arguments

data	dataframe. It can contain data with column names of "time" and "I"
time	character or numeric. The name of time variable in the dataframe. If the "data" parameter contains "time", this will be ignored. The unit must be in seconds.
I	cumulative infiltration (I) or infiltration rate (i) [mm]
a	constant
k	constant
group	character. The name of the group variables if the data is from different areas.
object	Model output object
...	Any other graphical parameter
x	a return object of the function.
xlab	x label of the plot
ylab	y label of the plot
main	Title of the plot
layout	plot layout

Value

• a: optimised constant

• k: optimised constant

• output: output of the group simulation

Author(s)

George Owusu

References

Kostiakov, A. N. (1932). On the dynamics of the coefficient of water-percolation in soils and on the necessity for studying it from a dynamic point of view for purposes of amelioration. 6.

Examples

data=read.csv(system.file("ext","sys","exampleBEST.csv",package="vadose"))
kostiakov1<-kostiakov(data=data,time="time",I="I")
#print(gof(kostiakov1))
plot(kostiakov1)
predict(kostiakov1)
coef(kostiakov1)
#gof(kostiakov1)

#group simulation
data=read.csv(system.file("ext","sys","infiltration2.csv",package="vadose"))
assin_breko<- subset(data, ID=="41A20_1")
kostiakovg<-kostiakov(data=data,time="minutes",I="CumInfil",group="ID")
coef(kostiakovg)

gowusu/vadose documentation built on May 17, 2019, 7:59 a.m.