Re: z_floor and z_ceiling (was Re: various observations)

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

Hans-Bernhard Br=F6ker wrote:

> Actually, the simplest explanation is probably the best here:  just=20
> state that ticlevels 0 and -1 correspond to the bottom and top of the z=
=20
> axis (_not_ the min and max, actually --- z axis can be reversed!), and=
=20
> that the coordinate moves linearly.
>=20
>> At this point though, changing the polarity might just confuse matters.
>=20
>=20
> This is not a question of what "might" happen.  The polarity in the 'se=
t=20
> ticslevel' parameter will not change, period.  I won't have script=20
> compatibility compromised.  What can be discussed is whether we should=20
> split up the old 'set ticslevel' and its alias, 'set xyplane <level>'.=20
> These two could have different scales.

OK people, any preference as to xyplane (not 'ticslevel') having bottom o=
f zrange as 0 and top of zrange as 1?

Right now, as the code exists, 'xyplane' and 'ticslevel' are synonyms.  T=
hat is "set ticslevel at -10" is valid even though the documentation indi=
cates that this is possible:

 Syntax:
       set ticslevel <frac>
       set xyplane <frac>
       set xyplane at <zvalue>
       show xyplane

Should "set ticslevel at <zvalue>" be allowed?  If not, then it is probab=
ly best to have enumerations of S_TICSLEVEL and S_XYPLANE, because there =
really isn't a nice way to determine what syntax cause the program to arr=
ive at the point in the case statement otherwise.

Dan