Re: "noreverse" is listed as option to xrange when it is no longer interpreted

[sfeam <sf...@us...>]

On Saturday, 23 May 2015 01:56:30 AM Daniel J Sebald wrote:
> I notice that even though "reverse/noreverse" has been deprecated, 

reverse/noreverse is deprecated only in the sense that its meaning
has been restricted to the originally documented case of autoscaling.

> the option setting "noreverse" appears in the list, i.e.:
> 
> Terminal type set to 'qt'
> gnuplot> show xrange
> 
> 	set xrange [ * : * ] noreverse nowriteback  # (currently [-10.0000:10.0000] )
> Might it be better to leave out the "noreverse" value?  

That tells you autoscaling on x will produce the 'normal' axis layout
with lower x values on the left side.  If it said instead
> 	set xrange [ * : * ] reverse nowriteback  # (currently [-10.0000:10.0000] )
that would indicate autoscaling will produce a layout with lower x values
on the right side.

>From "help set xrange":

 The `reverse` option reverses the direction of an autoscaled axis. For example,
 if the data values range from 10 to 100, it will autoscale to the equivalent of
 set xrange [100:10].  The `reverse` flag has no effect if the axis is not
 autoscaled. NB: This is a change introduced in version 4.7.


	Ethan



> It would be a 
> good "feature check" if the "noreverse" were no longer printed.
> 
> Of course, now that some versions have been released that do print 
> "noreverse", that sort of destroys the integrity of such a feature check.
> 
> However, even this is problematic:
> 
> gnuplot> set xrange [0:1] reverse
> gnuplot> show xrange
> 
> 	set xrange [ 0.00000 : 1.00000 ] reverse nowriteback
> 
> gnuplot> plot x
> 
> The "show" function is indicating xrange is reversed when clearly it 
> isn't.  So one can't rely on a set/show combination to determine if 
> reverse/noreverse is an acceptable syntax.
> 
> Well, don't use "reverse" keyword is the lesson, but gnuplot still 
> keeping track of reverse/noreverse and showing the option seems superfluous.
> 
> Dan