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Board » Technical Support » distance to go

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Posted by
Olive


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2012-12-24 20:22:03
2012-12-30 09:18:14 - Re: distance to go
That's all indifferent since the nonsense numbers lead us all astray. Who cares if it all makes sense when we "get close." Why play along at all. Sheeeze...
Posted by
RainbowChaser


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2009-06-14 09:44:50
2012-12-30 09:22:52 - Re: distance to go
evilonod - I can sympathise with your frustration, but rest assured there is no-one getting any advantage here. It really is all about the shape of the globe and how SOL's calculations are made.

Please don't give up on us!
Posted by
hmm


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2011-11-03 13:35:22
2012-12-31 10:06:10 - Re: distance to go
I believe I have now found the root cause of this problem. I have described it in my blog:

http://blog.sol.hmm.iki.fi/2012/12/scoring-problem-on-races-crossing-idl.html
Posted by
outlaw


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2012-06-01 13:37:55
2012-12-31 17:07:52 - Re: distance to go
As for the DTF calculations, how about simply calculating GC bearings to the next couple waypoints, then using GC distance to the best WP based on bearings + rounding direction. I suspect this may lessen server load as well. (see pic)
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Posted by
hmm


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2011-11-03 13:35:22
2013-01-02 11:45:03 - Re: distance to go
I have also tried to explain the DTF calculation in more detail in my blog, check the post here:

http://blog.sol.hmm.iki.fi/2013/01/dtf-calculation-problems-near-polar-area.html

As I say in the post, the DTF calculation is run every 15 seconds for each boat, so changes to that code have to be made very carefully not to cause the server too much load.

However, that doesn't mean that there will not be improvements in the future. It just means that the changes have to take into account also other things than only always getting the best possible DTF for the boat.
Posted by
Rod


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2010-06-24 22:30:48
2013-01-02 14:26:49 - Re: distance to go
Is it not possible for each player (sailor ?) to merely run the measuring caliper tool, in Great Circle mode, between the next turning mark and the current position of any boat (including his own) in which he has an interest?
I just do not understand the cause of all this worry over such a trivial problem.
Congratulation to Markku H. for solving the causes of the SERVER'S problem, but it is really not a problem to the SAILOR.
If it breaks, it's not strong enough--if it doesn't, it's too heavy.
Posted by
outlaw


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2012-06-01 13:37:55
2013-01-02 18:32:12 - Re: distance to go
> the DTF calculation is run every 15 seconds for each boat

This is unneeded, do a proper distance calculation every 16 steps, and use increments (VMC * timestep) inbetween.

That means only one in 16 boats gets a full calculation for a given timestep.

The same could be done for roundings, maybe.

--- Zuletzt bearbeitet von outlaw am 2013-01-02 18:33:23 ---
Posted by
hmm


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2011-11-03 13:35:22
2013-01-02 19:25:05 - Re: distance to go
To do that the VMC (and the course which to calculate VMC for) should be calculated for each boat every 15 seconds so it's not clear if it's easier to it that way.

The VMC, VMG etc numbers you see at the client are calculated at in your own computer and are thus "cheap" for the server but on the other hand are not available there directly.

It's good to have different ideas how to improve the calculation but as Rod wrote earlier I don't see it as a major problem now.
Posted by
Hasseballad


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2008-11-15 11:51:32
2014-05-25 07:33:33 - Re: distance to go
Recent experience at RTW2014-leg4. The "rounding line" ref. hmm for Cape Horn has a limit at 83S & 34W. Why not move that limit to say 65S & 64.2W or the exact W pos. on the "rounding line". Wouldn't that be a simple improvement for the boat position at the Horn specificly.

Rgds Hans

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