unfoldr (version 0.6.5)

simSphereSystem: Simulation of sphere system

Description

The function simulates a Poisson sphere system of intensity lam where each sphere center is uniformly distributed in a box. The function returns a list of spheres with elements id, center and radius r.

Usage

simSphereSystem(theta, lam, rdist, box = list(c(0, 1)), perfect = TRUE,
  pl = 0, label = "N")

Arguments

theta

simulation parameters

lam

mean number of spheres per unit volume

rdist

string, radii random generating function name

box

simualtion box

perfect

logical: perfect=TRUE (default) simulate perfect

pl

print level

label

some character as a label, `N` (default)

Value

list of class spheres if pl>100 or empty list

Details

Any random generating function, passed as a name, for the radii distribution is accepted as long as the formal function parameter names match the actual parameter names exactly as defined in the parameter list theta.

The simulation box is of type list. The vector arguments correspond to the lower and upper points in x,y and z direction. If box has only one element, i.e. list(c(0,1), the same extent is used for the other dimensions. The argument pl denotes the print level of information during simulation. Currently, only pl=0 for no output and pl>100 is implemented. Argument cond$rdist is of type string naming the (user defined) radii random generating function. Setting size equal to 'rlnorm' generates log normally distributed radii for a stationary Poisson ball system according to a general approach of perfect simulation (see reference below). Other distributions currently available are the beta, gamma and uniform distribution. Only simulations done by rlnorm can use the exact simulation type if perfect=TRUE otherwise it is ignored.

References

• C. Lantu\(\acute{\textrm{e}}\)joul. Geostatistical simulation. Models and algorithms. Springer, Berlin, 2002. Zbl 0990.86007

Examples

# NOT RUN {
 theta <- list("meanlog"=-2.5,"sdlog"=0.2)
 S <- simSphereSystem(theta,lam=1000,rdist="rlnorm",pl=101)
# }