Manual Page for Command >> GUESS


Syntax
>> GUESS (FILE: file_name)

Parent Command
> PARAMETER

Subcommand
-

Description
This command identifies initial guesses of the parameters to be estimated. The initial guess vector p0 is the starting point of the minimization algorithm (iteration k=0). Usually, the initial guess vector is identical with vector p* which holds prior information about the parameters. By default, p0 and p* are identical, taken from the TOUGH2 input file, and overwritten by command >>>> PRIOR. The starting point for the minimization algorithm may be different from the prior information vector. In this case, prior information is taken from the TOUGH2 input file, or must be provided through command >>>> PRIOR. The starting point is taken from this command which overwrites the initial guess provided through command >>>> GUESS.
A parameter is identified by an integer value indicating its position in the parameter block:

I XIGUESS(I)

This format is identical to that of file .par. Initial guesses can be provided either following the command line, or read from a file if keyword FILE is present. The filename is given after the colon. This latter option is useful to transfer best estimates from one inversion to another if the order of the parameters is the same.

Example
> PARAMETER
>> GUESS
2 0.345 (initial guess for parameter no. 2)
3 -16.971 (initial guess for parameter no. 3)
/* (the initial guess for parameter no. 1 is taken from the
fourth-level command >>>> PRIOR, or - if not present -
from the TOUGH2 input file) */
...

> PARAMETER
>> read GUESS from FILE: testi.par

See Also
>>>> GUESS | >>>> PRIOR


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Page updated: July 29, 1997