Purge Unused Variables
EES normally saves every variable defined during the work session regardless of whether or not it currently is in use when the Save or Save As command is issued. For example, if you define a variable X with the equation X=6 and later decide that the equation should read X1=6, EES will still keep the variable X and all of its characteristics in memory, e.g., guess value, bounds, units, format, and key variables comment. The Annual and Commercial EES licenses can store up to 3,000 and 6,000 variables, respectively. The Professional license allows 12,000 variables. The 64-bit Professional license provides 24,000 variables. Consequently, a small number of unused variables normally are not a concern. Where they can be a concern is when arrays are no longer being used, since an array can include a large number of individual variables. For very large problems, particularly problems using array variables, EES could run out of variable space.
The Purge Unused Variables command will examine the EES program and determine which variables are not in use. In addition, this command will determine if there are any Subprograms that are not in use. If either unused variables or Subprograms are detected they will be deleted (after a confirmation) and the memory that they required will be recovered.
The purging process is relatively complicated from a programming standpoint. Before using this command, it is a good idea to save a backup copy of your file, just in case a problem occurs during the purging process.