% Generated by roxygen2: do not edit by hand
% Please edit documentation in R/random_profile.R
\name{random_profile}
\alias{random_profile}
\alias{.lpp}
\title{Random Profile}
\usage{
random_profile(
  id,
  n = c(3, 4, 5, 6),
  min_thick = 5,
  max_thick = 30,
  n_prop = 5,
  exact = FALSE,
  method = "random_walk",
  HzDistinctSim = FALSE,
  SPC = FALSE,
  ...
)
}
\arguments{
\item{id}{a character or numeric id used for this profile}

\item{n}{vector of possible number of horizons, or the exact number of
horizons (see below)}

\item{min_thick}{minimum thickness criteria for a simulated horizon}

\item{max_thick}{maximum thickness criteria for a simulated horizon}

\item{n_prop}{number of simulated soil properties (columns in the returned
dataframe)}

\item{exact}{should the exact number of requested horizons be generated?
(defaults to FALSE)}

\item{method}{named method used to synthesize depth function ('random_walk'
or 'LPP'), see details}

\item{HzDistinctSim}{optionally simulate horizon boundary distinctness codes}

\item{SPC}{result is a \code{SoilProfileCollection} object, otherwise a
\code{data.frame} object}

\item{\dots}{additional parameters passed-in to the LPP (\code{.lpp})
function}
}
\value{
A \code{data.frame} or \code{SoilProfileCollection} object.
}
\description{
Generate a random soil profile according to set criteria, with correlated
depth trends.
}
\details{
The random walk method produces profiles with considerable variation between
horizons and is based on values from the normal distribution seeded with
means and standard deviations drawn from the uniform distribution of [0,
10].

The logistic power peak (LPP) function can be used to generate random soil
property depth functions that are sharply peaked. LPP parameters can be
hard-coded using the optional arguments: "lpp.a", "lpp.b", "lpp.u", "lpp.d",
"lpp.e". Amplitude of the peak is controlled by ("lpp.a + "lpp.b"), depth of
the peak by "lpp.u", and abruptness by "lpp.d" and "lpp.e". Further
description of the method is outlined in (Brenton et al, 2011). Simulated
horizon distinctness codes are based on the USDA-NCSS field description
methods
(\url{https://www.nrcs.usda.gov/wps/portal/nrcs/detail/?cid=nrcs142p2_054184}).
Simulated distinctness codes are constrained according to horizon thickness,
i.e. a gradual boundary (+/- 5cm) will not be simulated for horizons that
are thinner than 3x this vertical distance
}
\note{
See examples for ideas on simulating several profiles at once.
}
\examples{


# generate 10 random profiles, result is a list of SoilProfileCollection objects
d <- lapply(1:10, random_profile, SPC=TRUE)

# combine
d <- combine(d)

# plot
opar <- par(mar=c(0,0,3,2))
plotSPC(d, color='p1', name='name', cex.names=0.75)
par(opar)

# simulate horizon boundary distinctness codes:
d <- lapply(1:10, random_profile, SPC=TRUE, HzDistinctSim=TRUE)
d <- combine(d)

d$HzD <- hzDistinctnessCodeToOffset(d$HzDistinctCode)

opar <- par(mar=c(0,0,3,2))
plotSPC(d, name='name', color='p1', hz.distinctness.offset='HzD')
par(opar)


# depth functions are generated using the LPP function
opar <- par(mfrow=c(2,1), mar=c(0,0,3,0))

# generate data
d.1 <- lapply(1:10, random_profile, SPC=TRUE, n=c(6, 7, 8), n_prop=1, method='LPP')
d.1 <- combine(d.1)

# plot
plotSPC(d.1, name='name', color='p1', col.label = 'LPP Defaults')


# do this again, this time set all of the LPP parameters
d.2 <- lapply(1:10, random_profile, SPC=TRUE, n=c(6, 7, 8), n_prop=1, method='LPP',
           lpp.a=5, lpp.b=10, lpp.d=5, lpp.e=5, lpp.u=25)
d.2 <- combine(d.2)

# plot
plotSPC(d.2, name='name', color='p1', col.label = 'Custom LPP Parameters')


# reset plotting defaults
par(opar)



# try plotting the LPP-derived simulated data
# aggregated over all profiles
a <- slab(d.2, fm= ~ p1)
a$mid <- with(a, (top + bottom) / 2)

library(lattice)
(p1 <- xyplot(mid ~ p.q50, data=a,
              lower=a$p.q25, upper=a$p.q75, ylim=c(150,-5), alpha=0.5,
              panel=panel.depth_function, prepanel=prepanel.depth_function,
              cf=a$contributing_fraction, xlab='Simulated Data', ylab='Depth',
              main='LPP(a=5, b=10, d=5, e=5, u=25)',
              par.settings=list(superpose.line=list(col='black', lwd=2))
))

# optionally add original data as step-functions
if(require(latticeExtra)) {
  h <- horizons(d.2)
  p1 + as.layer(xyplot(top ~ p1, groups=id, data=h,
                       horizontal=TRUE, type='S',
                       par.settings=list(superpose.line=list(col='blue', lwd=1, lty=2))))
}



}
\references{
Myers, D. B.; Kitchen, N. R.; Sudduth, K. A.; Miles, R. J.;
Sadler, E. J. & Grunwald, S. Peak functions for modeling high resolution
soil profile data Geoderma, 2011, 166, 74-83.
}
\seealso{
\code{\link{profile_compare}, \link{hzDistinctnessCodeToOffset}}
}
\author{
Dylan E. Beaudette
}
\keyword{manip}