Re: Plans for gnuplot version 5 [per-line ranges]

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

On Tuesday, 22 April, 2014 22:57:01 Karl-Friedrich Ratzsch wrote:
> On 22.04.2014 08:13, Tait wrote:
> > In the current versions (4.6p3 or p5), the initial []-enclosed values
> > are taken as the overall x- and y- range.
> >   plot [5:11][3:12] x, x/2+4
> > is equivalent to
> >   set xrange [5:11]; set yrange [3:12]; plot x, x/2+4
> > and a range like [7:9] before the x/2+4 is a syntax error.
> > 
> > Changing this as outlined above (and apparently as-implemented in
> > CVS?) is incompatible because now the [3:12] above would be a syntax
> > error* and the [5:11] would apply only to the x and not to the x/2+4
> > line, and the overall plot x-range is still presumably at its previous
> > setting, or default [-10:10].
> 
> As far as i can see, the behaviour in 50 ist absolutely identical
> from the point of 4.6, also with your example.
> 
> But the new syntax with the "sample" keyword looks rather sketchy to me:
> 
>  plot sample [-1:0] -x, [0:1] x
> 
> Wouldn´t backward compatibility also be achieved by adding a keyword
> to "set xrange", e.g. "set xrange [0:1] axislength", meaning that
> the sampling is to be done per-line, and the axis length be taken
> from xrange?

The "sample [min:max]", as its name suggests, controls the axis being
sampled (usually t or x).  This is particularly relevant for parametric plots,
but does apply to function plots as well.  If you need to distinguish between
the sampled axis (t) and the x axis you can provide separate ranges for
each.   See "help plot sampling" 

> Oh, and i noted that replot still doesn´t accept an explicit range,
> even in "per-line" mode. Would that be possible?

Why would you ever need this?
Wouldn't "set xrange [min:max]; replot" do the same thing?
That's what zoom/unzoom does.

	Ethan