Path: csiph.com!eternal-september.org!feeder.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail
From: Ethan A Merritt <EAMerritt@gmail.com>
Newsgroups: comp.graphics.apps.gnuplot
Subject: Re: set range for second independent variable in special file '++'
Date: Sun, 26 Mar 2017 12:30:47 -0700
Organization: A noiseless patient Spider
Lines: 32
Message-ID: <ob94nq$vrh$1@dont-email.me>
References: <oao0pn$80p$1@solani.org> <oap0et$g16$1@dont-email.me> <oap546$3i0$1@solani.org> <oapapn$po7$1@dont-email.me> <oapaur$q4d$1@dont-email.me> <ob32kh$usr$1@solani.org>
Mime-Version: 1.0
Content-Type: text/plain; charset="ISO-8859-1"
Content-Transfer-Encoding: 7Bit
Injection-Date: Sun, 26 Mar 2017 19:27:54 -0000 (UTC)
Injection-Info: mx02.eternal-september.org; posting-host="105dddd0f1198f7d3ec43837d4f70be5"; logging-data="32625"; mail-complaints-to="abuse@eternal-september.org";	posting-account="U2FsdGVkX1+gLuNZfbn00Ek2BgvxcMdJ"
User-Agent: KNode/4.14.5
Cancel-Lock: sha1:l3DZSBauqsONVktxuuCEKTvCrlM=
Xref: csiph.com comp.graphics.apps.gnuplot:3596

Karl Ratzsch wrote:

> Am 20.03.2017 um 20:38 schrieb Ethan A Merritt:
>> Ethan A Merritt wrote:
>>> Karl Ratzsch wrote:
>>>> It seems I can only specify one independent variable with range for
>>>> '++'. Is that so?
>>>
>>> Yes, but...
>>> That's mostly because it's not clear how one could use it.
>>> If you have an example of a type of plot that this would allow,
>>> I'd be happy to look into adding it.
> 
> Hm, there are many, i think. The special filename "++" at the moment
> always directly maps the second independent variable to the y axis,
> but it could easily be meant to be sth else. Of course one can scale
> the values to the wanted sampling range in the "using" specifier, but
> you need a number of additional variables and it makes the script hard
> to read.

That much is a trivial change and I agree it is an improvement.

So as of today's CVS for the development version, '++' uses urange and
vrange for sampling rather than using xrange and yrange.
This does not by itself allow you to refer to the sampled variables
as "u" and "v" however, you'll still have to refer to $1 and $2.

I know of one minor downside to this change.
Currently you can't set u or v to log-scale, so with this change
you won't get nonlinear sampling on '++' even after "set log xy".
That can be added later.

	Ethan