February 2011 - Therion

CS and grid alignment
by Ben Cooper 16 Feb '11

16 Feb '11

Is there a way of turning off the grid alignment rotation for parts of a survey when using the CS setting? My survey is of a cave (Upper Flood) in the UK using cs OSGB (or EPSG:27700). Some sections have been copied in from a paper survey that is already aligned to Grid North, while other sections are new surveys where I have manually specified declination to Grid North. When turning on the cs setting, I've noticed that the cave is rotated, because Therion has assumed that my survey is aligned to magnetic North. I can see two solutions for the new survey section: 1) change all my declination settings to be True North rather than Grid North. In this case Therion will apply the final rotation to Grid North. 2) remove all my declination settings and allow Therion to determine these based on survey date. Howevver, I'd prefer not to have to edit all the source files and it still leaves the problem with the old paper survey that I traced. Is there something I can do within Therion to turn off the rotation to Grid North when using the cs setting? Regards, - Ben Cooper

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missing point +s partly resolved
by Bruce 14 Feb '11

14 Feb '11

>Any guesses as to which symbol-show (or other statement) directly effects the + part of the point symbol, as I would like to show them in both cases? I have figured this one out. One might expect the two statements. symbol-show point surface-station symbol-show point cave-station to have an identical net effect the same as. symbol-show point station but they do not. It seems like 'point station' is the '+' part of the station symbol, and 'point surface-station' is the special flag dependant part of the station symbol (like the entrance or doline or sink or continuation or arch symbols) and the text label. Not quite sure what unique attribute the 'point cave-station' might add - maybe the short stubby legs that point in the direction of the survey leg(?) So to get more complete information about the points to output to pdf, you need to include all three statements (assuming there is a 'symbol-hide group all' somewhere in your layout). At least I think it is something like this. I still have not figured out if the text associated with a surface point can be output if the point has no flags set. Bruce

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viewing files on a mac
by Graham Mullan 14 Feb '11

14 Feb '11

I have had two people complain to me recently that they cannot read lox files (or indeed survex 3d files) on their macs. I know that macs are poorly supported and, of course, all serious users should be on linux, or at worst Windows, but would it be possible to produce a browser plugin so that these poor benighted Apple fanboys can at least view the work of others even if they cannot contribute? Graham --- graham.mullan(a)coly.org.uk 0117 9502556 or 07887 637064 (or try 0844 2327803)

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cs suggestion: Outside bounds warning
by Andrew Atkinson 14 Feb '11

14 Feb '11

Hello A strange rotation was encountered relative to the grid, when playing with cs OSGB:SN and cs EPSG:27700 In the end this was tracked down to the fact that the 300000 400000, was still within all the fixes, which is wrong, but this put it well outside the SN area, and hence the rotation. (or that is what we think) Which lead me to the thought, maybe therion should warn, but continue if it finds an co-ordinate outside the area covered by the cs selected? Not sure if this is possible (easy) to do, but in this case would have saved lots of head scratching. Andrew

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Not all maps exported in some circumstances
by Bruce 12 Feb '11

12 Feb '11

Over the last couple of years I've noticed that I don't always get the maps and surveys I expect to be included in my pdf outputs. At long last I have teased the problem enough to be reasonably sure of it's characteristics. If I don't select any maps or surveys in my th-config file, then as I understood it all the maps in my source files should be exported to pdf. This was the meaning I took from the Therion book descriptions on page 45-46. What I find is that if I have map objects defined that contain scraps AND map objects defined that contain only centrelines (surveys), then the maps that contain only surveys are NOT output unless they are explicitly selected. If the reference to the maps that contain scraps are commented out, then the 'centreline maps' are suddenly output with out being selected. I thought this was contrary to the Therion Book description, and not behaviour that is particularly helpful. If one has gone to the trouble of defining a map with only a centreline or fixed points in it, then one would presumably want it exported when nothing is explicitly selected (which by default should select all). If I didn't want the centreline output, I would not have put it in a map object! To have Therion hide it can only cause confusion I think. So, I think now that I missed the subtlety in the following phrase. "If there is no map selected, all scraps belonging to selected surveys are selected by default for map export " as a map with no scraps is presumably not exported (although in my experience it is if there are ONLY maps with no scraps defined). If this is what is going on, perhaps we could have a new compiler statement like. select all-maps .to amend the current behaviour to select all maps (without having to select them individually) that have being defined regardless of whether they have scraps in them or not. Or perhaps there is already a way to do this? Bruce

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strike and dip
by Stacho Mudrak 10 Feb '11

10 Feb '11

Hi all, we are solving a problem of adding a basic geological observations (measurements) to therion. When measuring a planar feature (bedding or fault or others), you measure strike and dip. When measuring linear features, trend and plunge is measured. In the case of faults, also whether it is dextral or sinistral fault is determined and potentially a magnitude. My question is, do you have some idea/wish how to integrate these into therion? Do you have some experience with it? Our first idea is to add a standard T symbol for strike and dip measurement, but there is one problem. Orientation of this symbol is not drawn, but it is measured (with compass). But its position is given by position on the map. Should these measurements be entered into a table (as centerline data are), or put as options with symbols? Do you have any ideas or comments? Best regards, S.

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List of dig sites
by Andrew Atkinson 10 Feb '11

10 Feb '11

hi all One of the outputs that therion generates is a question marks list, which is very useful. Just a thought: There is a symbol for digs, so what about a digs list, or possibly combined, currently I am putting a dig symbol and a questionmark (which I make invisible) so that the digs appear on the question mark list. Andrew

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survey id bug
by Bruce 10 Feb '11

10 Feb '11

I have been using two letter codes as 'id' values for surveys. Eg aa, ab, ac, ad, etc ba, bb, bc, bd etc Finally I got to id, and I find I cannot make a map including this survey. Therion gives the error; :\Program Files\Therion\therion.exe: error -- id-BeyondPooh.th [349] -- not enough option arguments -- id -- must be 1 If I change the 'id' for the survey from id to idd or iD or ID it works perfectly. I presume this is a bug in 5.3.6 Bruce

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incomplete data sets
by Graham Mullan 10 Feb '11

10 Feb '11

I have begun the arduous task of converting a large data set (60 km+ of passage) from Survex to Therion in line with the rest of the data that we keep. Much of this is quite old, 1950s and 1960s. In many cases we do not have clino data and, in Survex, I have either ignored this fact or have manipulated the data by inserting fixes including altitudes at known points, usually entrances. This would skew the model to give a reasonable approximation of its 3d shape. I discover that Therion will not simply ignore the lack of clino readings but tells me that there is "not all data for given style" if I have put in this line "data normal from to length bearing ignoreall" This concerns me on two fronts: firstly does it mean that I have to go back in and type an arbitrary list of zeros at the end of each data line? Secondly, when it processes the cave does this mean that the process will give due meaning to all those zeros and adjust the model differently to how it would do so if they were not there (as in Survex)? Graham

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Irish Grid coordinates
by Graham Mullan 10 Feb '11

10 Feb '11

I am starting the tedious process of migrating a large dataset from Survex to Therion. Now would therefore seem the right time to start converting the co-ordinate system that is used. The data is for Co. Clare in Ireland and previously all entrances and fixed points were listed in Irish Grid. The Irish are changing this to ITM (Irish Transverse Mercator) and I would like this to be the system that we use as it is what will appear on their maps etc. I am assuming that it is not supported by Therion. I cannot find an EPSG number that specifically relates to this. The IOS website talks about their system being compatible with ETRF89, for Europe but that is the nearest indication I get. Can anyone tell me what the correct EPSG number might be or is it possible for ITM to be built into Therion as an option? Graham --- graham.mullan(a)coly.org.uk 0117 9502556 or 07887 637064 (or try 0844 2327803)

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