GSLIB Help Page: LUSIM

Description:

Creates Gaussianbased realizations with LU matrix method

Parameters:

datafl: the input data are in a simplified GeoEAS formatted
file.

icolx, icoly, icolz, and icolvr: the column numbers for
the x,y and z coordinates, and the variable to be
simulated. One or two of the coordinate column numbers can be set
to zero which indicates that the simulation is 2D or 1D.

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

idbg: an integer debugging level between 0 and 3. The higher
the debugging level the more output.

dbgfl: a file for the debugging output.

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

nsim: the number of simulations to generate.

nx, xmn, xsiz: definition of the grid system (x axis).

ny, ymn, ysiz: definition of the grid system (y axis).

nz, zmn, zsiz: definition of the grid system (z axis).

seed: random number seed (a large odd integer).

nst and c0: the number of variogram structures and the
isotropic nugget constant.

For each of the nst nested structures one must define it
the type of structure; cc the c parameter;
ang1,ang2,ang3 the angles defining the geometric anisotropy;
aa_hmax, the maximum horizontal range; aa_hmin,
the minimum horizontal range; and aa_vert, the vertical range.

Application notes:

This program requires standard normal data and writes standard normal
simulated values. Normal score transform and back transform are to be
performed outside of this program

Recall that the power model is not a legitimate model
for a multiGaussian phenomenon and it is not allowed in lusim

The semivariogram model is that of the normal scores.
The kriging variance is directly interpreted as the variance of the
conditional distribution; consequently, the nugget constant c0
and c (sill) parameters should add to 1.0.