Re: [ gnuplot-Patches-992149 ] String variables revisited

[Ethan A M. <merritt@u.washington.edu>]

On Sunday 18 July 2004 07:03 am, Hans-Bernhard Broeker wrote:
> > 3) user-defined string-valued functions.
>
> Users will almost certainly want to be able to do something like this:
>
> 	filename(i)=sprintf("foobar%d.ps", i)
>
> 	i=15
>
> 	# in a loaded file:
> 	set output filename(i)
> 	plot something
> 	i=i+1
> 	reread

But that example does not require a user-defined function.
That is the behaviour you would get anyway, courtesy of
the automagic string evaluation code already written.

filename = 'sprintf("foobar%d.ps",i)'
set output filename
i = 15
replot
i = 16
replot

What it does require (and your user-defined function would
also require) is that term.c:term_set_output() and a few other 
places in the actual drivers be modified similarly to what I did for
write_multiline(). They would need to check that the string is
not really a constant, but instead holds a sprintf() command. 

'set output <bar>' is messy because <foo> is used for something
other than being printed. Most of the other 'set <foo> "string const"'
require no special modification, since the fancy stuff happens inside
the eventual print routine. 


-- 
Ethan A Merritt
Department of Biochemistry & Biomolecular Structure Center
University of Washington, Seattle