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Board » Technical Support » distance to go

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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...
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!
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
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)
Attachments
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.
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.
> 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 ---
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.
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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The 636-mile Newport Bermuda Race is one of the oldest regularly scheduled ocean races, and with the Fastnet and the Sydney Hobart Race, it is one of the three great classic races of the yachting world. First raced in 1906, now in its 54th biennial, the Race can again also be participated in online. In real life, the race is open to entry in four different division – Double-Handed, St. David's Lighthouse, Gibbs Hill Lighthouse, and Finisterre Division – which in the past we have also offered online. This year, however, our online race will be all-in one-design in silky swift Club Swan 50 yachts, so that your results can count towards SOL’s SUPerBUDdy title, whilst hopefully still giving you a chance of overall line honours against the fastest yachts of the real-life Gibbs Hill Division, especially if you can find some forecast winds that don’t quite work out that way on the real water!
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Get ready to tackle the North Sea as we sail from Norway’s stunning outer Korsfjorden to the rugged Shetland Isles! Welcome to an exciting new chapter for this classic 190-nautical-mile ocean route, bringing our global community together for a true test of strategy and seamanship.

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