2.5.4.2 environment variables

The environment variables must be defined before `gnuplot` is executed; how to do so depends on your operating system.

      FIT_LOG

changes the name (and/or path) of the file to which the fit log will be written from the default of "fit.log" in the working directory. The default value can be overwritten using the command `set fit logfile`.

      FIT_SCRIPT

specifies a command that may be executed after an user interrupt. The default is replot, but a `plot` or `load` command may be useful to display a plot customized to highlight the progress of the fit.