[Therion] Question about "\cavedepth" and Northarrow

Bruce bruce at tomo.co.nz
Thu Apr 3 21:19:09 CEST 2014

If indeed the 'cave' you have entered has a depth range between -15m and
-20m, then I would expect the depth to be reported as (+)5m.  (I presume
this is a sea cave, with altitudes below sea level - but it would also be OK
if you are using an arbitrary altitude datum).

Same as a dry cave that starts at 100m and descends to 95m.  It's depth
would be reported as (+)5m, not 100m.

Maybe the solution for you is to add altitude points to the wall near each
end, so that the altitudes are plotted directly on the map.

Or you could add a (manual) map-comment to the header "maximum depth: 20m"

Another idea, therion may store variables that define the maximum coordinate
range.  If so, then it would simply be a matter of a small metapost to
report the minimum altitude.  Stacho? Martin?


-----Original Message-----
From: therion-bounces at speleo.sk [mailto:therion-bounces at speleo.sk] On Behalf
Of Torsten Schnitter
Sent: Friday, 4 April 2014 2:28 a.m.
To: therion at speleo.sk
Subject: [Therion] Question about "\cavedepth" and Northarrow

Hi all

I'm wondering a bit about the results from the variable \cavedepth.
May be it's not correct this way or I do have a different understanding and
someone can explain to me why it is this way.

I'm drawing a map (with scraps, points, walls etc) containing just a
of the entire cavesystem.
Concerining the survey data I'm using "data diving ..." within centerline.

The result from \cavedepth is now the maximum difference between the
and deepest point of that part of the cave.
E.g.: If I have surveypoints in this part of the cave from -15m to -20m the
result in the header using \cavedepth is -5m.
What I did expect to get from \cavedepth was the maximum depth of this part
the cave, so -20m.
Because this is the relevant info to cavedivers.

Is there any way to get this result without using the override from
I would like to use the automatic calculation of course but also want to get
maximum depth under water.

2nd question:
I would like to use a northarrow as you can see in the attached file.
Does anyone have some code for that?

Thanks for your help.


More information about the Therion mailing list