- Therion - speleo.sk

SD Units for fixed points
by Carl Magnuson 19 Dec '08

19 Dec '08

Hello, I was wondering what units the standard deviations are for fixed points - the same units you are using for the rest of your data input, or the units your fixed point is in (UTM15 for example)? It doesn't seem to be documented in the manual or elsewhere. Thanks, Carl

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standard deviation and survey grade
by Bruce Mutton 17 Dec '08

17 Dec '08

Time has come to assign my least accurate survey data a lower accuracy! I'm curious as to how Therion deals with the std deviations. Had a look, but can not find much more than is in the Therion book. First, what are the default values adopted by Therion? Currently I have only one survey in a large(ish) dataset that has been allocated sd's. From a casual look at the distortions it clearly works - in that a nice result is obtained with more distortion in the lower accuracy area. I guess that if the default values are zero, then all the distortion would be forced to an area given non-zero sd's; Is this how it works? In this case it would seem that if one survey parameter has a sd setting, all the surveys should all have their respective settings allocated for this parameter to more accurately model a realistic distribution of corrections. Second, has anyone made any attempt to associate sd values with recognised cave survey grades (bcra grades for example). Here is my off the cuff assessment of what in NZ some people call bcra5 but is really well short. grade NZBCRA4 # Bruces assessment of the BEST typical NZ surveying practice MIGHT achieve tape length 0.1 meter # ie -0.2m to +0.2m for measurement to chest to 0.1m compass bearing 1 deg # ie -2 deg to +2 deg for sighting to light of person on station to 1 deg gradient clino 1 deg # ie -2 deg to +2 deg for sighting to light of person on station and sometimes accounting for 'eye to light' offset to 1 deg endgrade I suspect the sd's may often be larger than this. The actual sd for polar measurements probably depends a lot on the average length of the legs I expect Thanks Bruce

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survey-level: Minor correction /clarification of entry in Therion Book
by Bruce Mutton 09 Dec '08

09 Dec '08

Just looking for a clarification of the following entry copied from pg 51 of the Therion Book. (text copy and image copy) _ survey-level <N/all> . how many surveys to display with stations. There seems to be a formatting issue, but more importantly it's function. I'm being lazy here and have not experimented. I assume it's related to the debug statement used in layouts. Does it control the display of the nested level of survey? Eg 126 versus 126(a)f.Greenlink.RiwakaSystem If so I assume the default is N for none, based on my experience so far. Is this correct? Bruce

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Two minor bugs in metapost defs
by Xavier Pennec 09 Dec '08

09 Dec '08

I found a few bugs in the metapost definitions that could be usefully corrected in the next versions: In the subtype clay of wall, "Pickup PenA" is missing before drawing the wall line at the end, and the effect is that the line is drawn with PenC (thin). def l_wall_clay_SKBB (expr P) = T:=identity; cas := 0; dlzka := arclength P; mojkrok:=adjust_step(dlzka, .5u); pickup PenC; q := (-0.15u,0){up}..{down}origin..{up}(0.15u,0); forever: t := arctime (cas + mojkrok/2) of P; thdraw q shifted (point t of P + .25u * unitvector(thdir(P,t) rotated -90)); cas := cas + mojkrok; exitif cas > dlzka - (2*mojkrok/3); % for rounding errors endfor; >>>>> Pickup PenA thdraw P; enddef; I also noticed that sometimes the margin around a text is changed by the presence (or absence) of a point label. After many trials, I finally identified that it comes from the value of bboxmargin which is reset in process_label. It seems to me that an interim is missing before resetting bboxmargin in order to keep this change localized. def process_label (expr cent, rot) = begingroup <<<< bboxmargin:=0.8bp; >>>> interim bboxmargin:=2bp; q:=((bbox lab) smoothed 2) rotatedaround (cent, rot); draw lab rotatedaround (cent, rot); write_circ_bbox(q); % without corners smoothing it was enough to use % write_bbox(q); endgroup; enddef; Xavier

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Austrian Symbol-Set
by Georg Pacher 26 Nov '08

26 Nov '08

Hi there! I am about to adapt the symbol-set in therion to meet the Austrian standard (see http://www.hoehle.org/downloads/signaturen.gif) The changes I made, can be found here: ftp://ftp.tugraz.at/outgoing/therion/symbolsetAUT_changes.zip and an example of what comes out: ftp://ftp.tugraz.at/outgoing/therion/types_AUT.pdf Most symbols are finished already (or met the standard anyway), but there are still some open issues: -Drawing the symbol for entrance pits which uses a double line. Currently I generate points at a fixed distance perpendicular to the given line and connect them to form the inner line. This results in very bad behaviour at edges, and needs a lot of memory due to the large number of generated points. Any ideas how to solve that? -Naming of floorstep subtypes: As in the old UIS standard(?) there are floorstep subtypes when equipment is needed (<10m, >10m). Any ideas for a good (short) name for those? -Legend symbols/explanations. I didnt really care about that yet. And the main question is: - How shall I prepare the changes I did, such that they can be easily included in one of the next releases? Keep up the good work and kind regards Georg.

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Xtherion interface point data entry differs to other entity types
by Bruce Mutton 26 Nov '08

26 Nov '08

A quirk of Xtherion that still gets me from time to time is that the behaviour of point data entry seems to be differ to the behaviour when entering lines or areas, at least within Windows OS. Typically, I decide that, for example, I want to draw some lines of type rock-border, so my sequence will be; 1. Ctrl+L (enter insert line mode and 'lines' menu area on right is activated) 2. Select 'rock-border from the Lines type dropdown listbox and press enter 3. If there are any other options I will enter them now, such as -clip off for example 4. Left-click a sequence where I want the rock-border to appear, then tick the reverse and close tick-boxes if necessary 5. Select each line-point node and smooth it using the drag handles 6. Repeat for other nearby rock-borders Steps 1 to 5 apply for all line types I think. Steps 1 to 4 apply similarly for allocating areas to previously defined lines. There are other sequences that can be used, but this seems fairly efficient if tracing a scanned sketch, and fits one of the ways my mind likes to work. Entering POINTS in this sequence, however, results in an undesirable side effect at step 2. The 'points' menu area on the right is NOT activated (unless of course the previous action resulted in a point being selected) So, if the points menu IS NOT active, you must left-click the point position, THEN select the type of point and it's options/properties; OK, but it does not follow the consistent sequence above. Alternatively if the points menu IS active and you follow the steps above, the result is that the previously selected point type and properties will be LOST and changed to the type and properties that you enter in steps 2 and 3. This inconsistency slowed my learning to use Xtherion considerably (to a beginner it appeared to rarely work the same way each time) and even now results in unexpected map contents from time to time. Is there 'design' behind this behaviour and I am just not using it as intended? Or is there a bug in that activating insert point mode does not activate the 'points' menu area and deselect the previously edited point? This behaviour has been present in all releases since I first used Therion just over a year ago. Bruce

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Loch Units
by Jonny Prouty 25 Nov '08

25 Nov '08

I have a quick and hopefully simple question. How do I make therion output a loch model with imperial units as opposed to metric? The units in the survey are set to feet, but therion is interpreting them as meters. Any ideas? Thanks in advance! -Jonny ^v^

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georeferencing data added to pdf maps
by Bruce Mutton 21 Nov '08

21 Nov '08

I notice in the changes.txt file for 5.2.3 mentions "georeferencing data added to pdf maps" Is this intended to mean that the output co-ordinate system can be printed in the legend, or something more sophisticated? Printing the output co-ordinate system in legends generally and the 'caves list' would be useful (their common names and or their 'numerical' name) Bruce

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Continuation Tesxt Keeps Repeating
by Bruce Mutton 13 Nov '08

13 Nov '08

And to continue a theme, something I noticed with 5.2, and also with 5.2.2 In the picture below, I have defined two continuations with the text "water enters" (the bottom right-most continuations) similar to the following; point 312.75 -1284.5 continuation -text "water enters" -attr code V -explored 0 The problem is it turns up in continuations defined simply with point 123.0 456.0 continuation As you can see there are at least three unwanted instances . The same thing is going on with the 'tight' continuation text on the left of the picture. I have attached a continuations list for the whole cave for reference (you can see I haven't started using it properly yet, but I hope to in due course) My mistake or a bug? Bruce

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Length and depth of caves with no (therion) survey data
by Bruce Mutton 12 Nov '08

12 Nov '08

.and using the same example. I have two caves that have "known" lengths and depths (subject perhaps to resurvey one day) in amongst three that are in the process of having surveys and drawings made in Therion. For example the tourist cave and Perseverance cave listed below. For the tourist cave there is no map, but I have entrance co-ordinates, and so to the entrance station I have given the 'accepted length' an 'explored' flag. Perhaps it would be better entered as 'approx' (it would then be included in the 'length') but I can not see how to do this. Also is there no way to enter a depth? For Perserverance cave I have a scanned map with associated surveyed length and depth. This prints out nicely in my 2d outputs but in the table below I have not yet entered length and depth, although could take the same approach as with the tourist cave. Similarly it would seem best to enter as 'approx', but again I don't know how to do without the benefit of actual survey legs entered. So, just wondering a) if this scenario has been considered and b) how have others dealt with it. Overall it would seem best to be able to have therion output realistic data, but not allow users so much leeway that the meaning of the various headings (length, depth, explored, approx, surface) becomes meaningless. Bruce

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