# Update

This command updates the current values of variables stored in the given file, which has to be formatted as an initial-value file (as described in the fit section).

If the file name does not exist, a new file is created containing all currently defined user variables. All variables not used in the last fit are marked as `"`#FIXED`"`. This is useful for saving the current values of fit variables for later use or for restarting a converged or stopped fit.

Syntax:

         update <filename> {<filename>}

If a second filename is supplied, the updated values are written to this file, and the original parameter file is left unmodified.

Otherwise, if the file already exists, gnuplot first renames it by appending .old and then opens a new file. That is, `"`update 'fred'`"` behaves the same as `"`!rename fred fred.old; update 'fred.old' 'fred'`"`. If renaming is not possible because that file already exists, update aborts with an error message. [Renaming is not done at all on VMS systems, since they use file-versioning.]

Please see fit (p. ) for more information.