## GSLIB Help Page: ANNEAL

Description:
- This program requires an integer-coded training image, a series of initial integer-coded realizations (possibly only one) to post-process, and information about what components of a two-point histogram are to be reproduced. The integer coding could be derived naturally from a categorical variable or it could be derived from the discretization of a continuous variable.
Parameters:

- datafl: a file that contains the input realizations to post-process. The realizations must be integer-coded. The maximum number of different integer codes is specified in `anneal.inc`. The input file has one integer per line cycling fastest on x, then y, then z, then by realization.
- trainfl: a file with the training image. The training image must have the same integer code values as the realizations to post-process and have the same size and discretization.
- idbg and report: an integer debugging level between 0 and 3, and a reporting interval. After a fixed number of iterations (report) the realization is written to the output file.
- dbgfl: file for the debugging information.
- outfl: the output file that will contain the post-processed realizations.
- nsim: the number of initial realizations to post process.
- nx, ny, and nz: definition of the grid system.
- seed: random number seed (a large odd integer).
- maxit and tol: the maximum number of iterations over the entire grid network. Typically 99\% of the improvement is reached in 5 iterations and the remaining 1\% may be reached by 10 iterations. More than 10 iterations is not recommended. The initial objective function is normalized to one; when it is lowered to tol the simulation is stopped.
- ndir: the number of directions for the two-point histogram control. For each direction the following parameters are needed:
  - ixl: the offset in the x direction for a unit lag
  - iyl: the offset in the y direction for a unit lag
  - izl: the offset in the z direction for a unit lag
  - nlag: the number of lags