therion.log: What does "Survey has 2 connected components" mean?
Below is a part of the therion.log file. It says "Survey has 2 connected components." What is this? It also says that there are 87 loops. But when I count them in therion.log, there are 86 (which should be correct, I think: 3007-2922+1). If I rearrange (sort) the centerline data, and compile again, - the sentence is gone. It says that there are 86 loops (a part of that therion.log is shown below s well). Not important issue, - just wondering ... Torstein Finnesand Norway ------------------------ 1> Survex 1.1.12 2> Copyright ¸ 1990-2007 Olly Betts 3> Survey has no fixed points. Therefore I've fixed 1 at (0,0,0) 4> 5> Survey contains 2922 survey stations, joined by 3007 legs. 6> There are 87 loops. 7> Survey has 2 connected components. 8> Total length of survey legs = 21916.41m (21921.70m adjusted) 9> Total plan length of survey legs = 19741.99m 10> Total vertical length of survey legs = 8090.64m 11> Vertical range = 492.90m (from 142 at 329.28m to 2049 at -163.63m) 12> North-South range = 1012.65m (from 142 at 801.56m to 1730 at -211.09m) 13> East-West range = 1084.57m (from 1269 at 700.47m to 2552 at -384.10m) 14> 412 1-nodes. 15> 2007 2-nodes. 16> 436 3-nodes. 17> 56 4-nodes. 18> 10 5-nodes. 19> 1 6-node. 20> ------------------------------------ 1> Survex 1.1.12 2> Copyright ¸ 1990-2007 Olly Betts 3> Survey has no fixed points. Therefore I've fixed 1 at (0,0,0) 4> 5> Survey contains 2922 survey stations, joined by 3007 legs. 6> There are 86 loops. 7> Total length of survey legs = 21916.41m (21921.71m adjusted) 8> Total plan length of survey legs = 19741.99m 9> Total vertical length of survey legs = 8090.64m 10> Vertical range = 492.90m (from 728 at 120.11m to 961 at -372.79m) 11> North-South range = 1012.64m (from 728 at 367.41m to 599 at -645.23m) 12> East-West range = 1084.57m (from 1114 at 760.12m to 1121 at -324.45m) 13> 412 1-nodes. 14> 2007 2-nodes. 15> 436 3-nodes. 16> 56 4-nodes. 17> 10 5-nodes. 18> 1 6-node. 19>
On Tue, Feb 09, 2010 at 10:10:24PM +0100, Torstein Finnesand wrote:
Below is a part of the therion.log file. It says "Survey has 2 connected components." What is this?
It means (Survex thinks) there are two survey networks which are connected within each other, but not to each other. So two separate caves, each fixed by a GPS fix for example. But your survey has no fixed points (just an invented one) so that shouldn't work. You need at least as many fixed points as connected components.
It also says that there are 87 loops. But when I count them in therion.log, there are 86 (which should be correct, I think: 3007-2922+1).
The formula used is: #legs - #stations + #connected_components So the bug here is that it is deciding there's a second component.
If I rearrange (sort) the centerline data, and compile again, - the sentence is gone. It says that there are 86 loops (a part of that therion.log is shown below s well).
There must be something about the first arrangement which the colouring algorithm used to find the components isn't handling. If you're willing/able to send me the first dataset, or a cut down version which Survex still incorrectly claims to have 2 connected components, that would be very helpfully in tracking this down. Cheers, Olly
participants (2)
-
Olly Betts -
Torstein Finnesand