## GSLIB Help Page: KB2D

Description:

- This is a straightforward 2-D simple and ordinary kriging subroutine that can be used as is or as a basis for custom kriging programs.

Parameters:

- datafl: the input data in a simplified Geo-EAS formatted file.
- icolx, icoly, and icolvr: the columns for the x and y coordinates, and the variable to be kriged.
- tmin and tmax: all values strictly less than tmin and greater than or equal to tmax are ignored.
- idbg: an integer debugging level between 0 and 3. The higher the debugging level the more output. Normally level 0 or 1 should be chosen. If there are suspected problems, or if you would like to see the actual kriging matrices, level 2 or 3 can be chosen. It is advisable to restrict the actual number of points being estimated when the debugging level is high (the debugging file can become extremely large).
- dbgfl: the debugging output is written to this file.
- outfl: the output grid is written to this file. The output file will contain both the kriging estimate and the kriging variance for all points/blocks. The output grid cycles fastest on x and then y
- nx, xmn, xsiz: definition of the grid system (x axis).
- ny, ymn, ysiz: definition of the grid system (y axis).
- nxdis and nydis: the number of discretization points for a block. If both nxdis and nydis are set to 1 then point kriging is performed.
- ndmin and ndmax: the minimum and maximum number of data points to use for kriging a block.
- radius: the maximum isotropic search radius.
- isk and skmean: if isk0 then simple kriging will be performed with a mean of skmean
- nst and c0: the number of variogram structures and the isotropic nugget constant. The nugget constant does not count as a structure.
- For each of the nst nested structures one must define it, the type of structure; cc, the c parameter; ang1, the azimuth of the maximum range; aa_hmax, the maximum range; and aa_hmin, the minimum range. A detailed description of these parameters is given in section II.3.