GSLIB Help Page: PFSIM

Description:

The pfsim program is for simulation of categorical or
continuous variables with pfield simulation.

Parameters:

vartype: the variable type (1=continuous, 0=categorical)

idist: if set to 1, then the conditional distributions are taken
to be defined by indicator thresholds. If set to 0, then the
conditional distributions are Gaussian requiring a mean and variance

ncat: number of thresholds or categories (idist=1 or
vartype=0)

cat: the threshold values or category codes (there should be
ncat values on this line of input)

datafl: the data file containing zdata that provides the
details between the IK thresholds. This file is used only if table
lookup values are called for in one of the interpolation/extrapolation
options.

icolvr and icolwt: when either ltail, middle or
utail is 3 then these variables identify the column for the
values and the column for the (declustering) weight in datafl
that will be used for the global distribution.

zmin and zmax: minimum and maximum data values allowed.
Even when not using linear interpolation it is safe to control
the minimum and maximum values entered. The lognormal or
hyperbolic upper tail is constrained by zmax

ltail and ltpar specify the extrapolation in the lower
tail: ltail=1 implements linear interpolation to the lower limit
zmin; ltail=2 implements power model interpolation, with
w=ltpar, to the lower limit zmin; and
ltail=3 implements linear interpolation between tabulated
quantiles.

middle and midpar specify the interpolation within the
middle of the distribution: middle=1 implements linear
interpolation to the lower limit zmin; middle=2 implements
power model interpolation, with w=midpar, to the lower
limit zmin; and middle=3 allows for linear interpolation
between tabulated quantile values;

utail and utpar specify the extrapolation in the upper
tail of the distribution: utail=1 implements linear interpolation
to the upper limit zmax, utail=2 implements power model
interpolation, with w=utpar, to the upper limit
zmax; utail=3 implements linear interpolation between
tabulated quantiles; and, utail=4 implements hyperbolic model
extrapolation with w=utpar.

distfl: input data file with the conditional distributions.

imean and ivar: columns for the Gaussian ccdf means and
variances (idist=0) or the ccdf values (idist=1).

tmin and tmax: all values strictly less than tmin
and strictly greater than tmax are ignored.

pfile: file containing the input pfield probability realizations

icolp: column number in pfile for the pfield probability
value.

pflag: if set to 0, then the pfield probability values are taken
to be Gaussian deviates that need to be converted to cumulative
probability values. If set to 1, then the pfield probability values
are already cumulative distribution values between 0 and 1.

outfl: the output grid is written to this file. The output
file will contain the results, cycling fastest on x,
then y, then z, then simulation by simulation.

nsim: number of realizations

nx, ny, and nz: size of the simulation grid
A short description of the program