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(gnuplot.info)adjustable parameters

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Enter node , (file) or (file)node

 There are two ways that `via` can specify the parameters to be adjusted,
 either directly on the command line or indirectly, by referencing a
 parameter file.  The two use different means to set initial values.

 Adjustable parameters can be specified by a comma-separated list of variable
 names after the `via` keyword.  Any variable that is not already defined is
 is created with an initial value of 1.0.  However, the fit is more likely
 to converge rapidly if the variables have been previously declared with more
 appropriate starting values.

 In a parameter file, each parameter to be varied and a corresponding initial
 value are specified, one per line, in the form
       varname = value

 Comments, marked by '#', and blank lines are permissible.  The
 special form
       varname = value       # FIXED

 means that the variable is treated as a 'fixed parameter', initialized by the
 parameter file, but not adjusted by `fit` (Note: fit ).  For clarity, it may
 be useful to designate variables as fixed parameters so that their values are
 reported by `fit`.  The keyword `# FIXED` has to appear in exactly this form.