*****************
**Initial Guess**
*****************

::

	Initial Guess = {char_string} [filename]

-----------------------
**Description / Usage**
-----------------------

This optional card directs the initialization of the entire unknown vector. Three options
are provided to set the entire solution field to numerical values determined by
{char_string}. Three additional options are available for reading initial values of the
solution vector from data files. The permissible values of {char_string} are:

zero                          
    For an initial guess of zero (0.) for each degree of freedom in the unknown
    vector.

one                           
    For an initial guess of one (1.) for each degree of freedom in the unknown
    vector.

random                        
    For a random initial guess (between 0. and 1.) for each degree of freedom
    in the unknown vector.
    
read                          
    To obtain the initial guess by reading the ASCII data file identified as
    the *GUESS file*, which must have initially been a *SOLN* file or a tmp_i.d
    (*Write Intermediate Results*) file.

read_exoII                    
    To obtain the initial guess from the EXODUS II file specified by the *FEM
    file* card that is also used to supply mesh data. Any extraneous variables
    in the EXODUS II file that are not in the list of active variables for the
    current problem description are simply ignored.

read_exoII_file *file name*   
    To read the initial guess for the field variables from an EXODUS II
    database file different from the initial mesh database file. The
    *file_name* is specified as a single string following the read_exoII_file
    keyword. As with the read_exoII option, any extraneous variables not
    specified as active variables for the simulation will be simply ignored.

If this card is omitted, then the default behavior is to assume that a value of zero has
been specified for {char_string}.

------------
**Examples**
------------

Following is a sample card:
::

	Initial Guess = zero

::

	Initial Guess = read_exoII_file      First_Iteration.exoII

-------------------------
**Technical Discussion**
-------------------------

This card provides the specification of the initial vector of unknowns in a problem. In
most cases this vector is specified to be identically zero, though in some cases a nonzero
vector may be of value (see *Technical Discussion* section of *Debug* card). The first
three options (**zero, one, random**) employ an internally-generated vector of initial
values, while the **read** option utilizes the values read from an ASCII solution file (see
*SOLN* input card) previously calculated by *Goma*, and the **read_exoII** options employ
solutions read from binary (exoII) files, not necessarily always generated by *Goma*.