Re: MISSING and UNDEFINED

[Daniel J S. <dan...@ie...>]

Just brainstorming here:

> I propose there should be two types of classification strings
> 
> set datafile missing ""
> set datafile undefined ""

 Syntax:
       set datafile missing {"<string>"} {ignore | increment}
                            {connect | break}
       show datafile missing
       unset datafile

where "ignore" means to ignore any point containing the string "<string>", "inc" means to increment any datum fields (useful for leaving spaces in histograms); "connect" means to draw over the point for continuous styles as though the point wasn't present connecting points on either side(s), "break" means to not connect any points present on either side(s) (useful for placing discontinuities in lines).  The default for "missing" is ignore/connect.

The syntax for "undefined" would be similar except the default would be increment/break.

You've probably noticed that there is no difference here other than titles "missing" and "undefined"; we'd just be providing two flags for the user to control.  So really, an alternative would simply be to have a general "flag", e.g., "set datafile flag "NaN" increment break" for which there could be multiple flags.  But, in some sense I kind of like the missing/datafile in that it provides the flexibility but provides just a tad of assumptions (the defaults) to help the user.

Dan