Zezo forum:

Post by zezo | 2017-09-30 | 21:05:43

Hi,

I've rewritten the polar extraction to make use of the new data format.

Race support is available at http://zezo.org/t650v3/chart.pl

I've also left the old version in place just in case.

Please keep the thread on topic. Thank you!

51 Comments

Post by zezo | 2017-09-30 | 21:14:46

Some details:

Polars seem to be a bit faster as a whole, even for the basic sails.

"Pro sails" assumes all available options. Hull polish adds 0.3% speed. The foils add 4% between TWA 80 and 160, TWS 16-35.

[edit] renamed "pro sails" to "full extra pack"

Tack/Gybe/sail change penalty is 0.93/10 minutes for pro and 0.75 with std winches (game parameters are 50% performance for 75/300 seconds)

P.S. I found a bug in the old version - if the optimum TWA is 45 the boat won't sail at TWA 50. It would jump right to 55. Not a big deal, but can be seen when comparing the two tracks.

The update minute is assumed to be 0. When comparing wind speeds you should keep in mind the exact moment of time. The game UI probably shows the wind speed interpolated down to the minute. The router still runs in 10-minute steps.

Post by pmangino | 2017-09-30 | 22:09:11

Thx Cvetan, great work, as always.
Any plans to update the interface chrome extension with the 3D tool..? Or we will have to find boat position manually.
Best regards,
Princess Marina

Post by zezo | 2017-09-30 | 22:50:06

It looks like Chrome does not support the new communication, but it could be possible to do it in Firefox. But that has additional complications for me, because firefox extension auto-update requires SSL, and installing SSL for zezo.org is a bit complicated. I can find a workaround, but it won't happen in a day.

Post by QuiVaSadoVaMaso2 | 2017-09-30 | 23:04:44

Thanks Cvetan, great job !
Olivier
Mousse Line
or
QuiVaSadoVaMaso

Post by Gondolero-LDLN | 2017-10-01 | 13:18:05

Thanks Cvetan.
Keep up the good job :-)

Regards,
Pablo.
Gondolero-LDLN

Post by taberly | 2017-10-01 | 14:27:01

A big thank you Cvetan!
for your great work and for all the info you give us !!

eric

Post by GeGaX | 2017-10-01 | 16:25:16

Hi Cvetan,
It would be cool if the options were separate ...
So everyone can activate them depending on which ones he has chosen.

Personally I have not taken the 3 sets of sails but I have the winches, foils and polish
So I can not activate them, I have some options but not configurable on zezo :(

Post by zezo | 2017-10-01 | 17:59:00

Most of the time those 5% don't affect the general strategy. Sometimes the optimum TWA is different between pro and the default sails and you have to check the proper polars, but other than that the actual change in the weather is usually bigger than the boat speed difference.

Post by Inicio | 2017-10-01 | 22:55:55

Do we have confirmation of the times at which the weather is updated?

5:30; 11:30 etc?
If yes, I suppose it's UTC...

Perhaps also the interpolated 8:30; 14:30; ...

Post by zezo | 2017-10-01 | 23:06:05

That's about the end of the update in UTC. But it happens gradually starting at 3:30, 9:30 ...

Or maybe we better say it's the start of the update in CE(S)T

So if you need a short-range forecast you can check at 3:40 or 4:00 for few hours more.

At 00, 06, 12 and 18 CEST there are about 96 hours of new forecast available.

Post by Inicio | 2017-10-01 | 23:07:59

Thanks!

Post by toxcct | 2017-10-02 | 11:00:07

Hi Cvetan,

Did you change anything to polars.js at all, on did you upgrade only the polars compiler (which is not available publically AFAIK) ?

I've retrieved your latest ideal.png and my display got broken... I'll have a deeper look later, but just curious about it.

Thanks.

Post by zezo | 2017-10-02 | 13:06:20

Broken like deep gaps here and there? If that - it's the file size/max wind speed/array dimensions (if you happen to have usezd 50knot png)

Other than that it's only the sail encoding 0..n instead of 1 .. 2^n

Edit: Probably not this. I got the problem yesterday because I used old conversion script, but it looks like all online versions use 130x181 files.

diff says mostly

> var colors = ["#ff0000", "#00ff00", "#0000ff", "#ff2000", "#00a000", "#b00000", "#d77900" ]
> var sails = ["Jib","Spi","Stay","LJ","C0","HG","LG"];

Post by toxcct | 2017-10-03 | 17:55:51

I'm looking at it right now.

Just to let you know, it appears like some of the sail are not recognized :
http://toxcct.free.fr/polars/

Post by toxcct | 2017-10-03 | 18:14:38

Ahhhh, ok got it.
The sails are not indexed as powers of 2 (1, 2, 4, 8, 16, 32, 64) anymore :)

Thanks

Post by Michel | 2017-10-03 | 20:18:53

It seem that WR change le position of boat !
Now it is N-S and after E-W like a normal position and not EW & NS after !
VR is going on the light !

May be once time a VR play on the facebook game play ?

Post by zezo | 2017-10-03 | 20:43:17

Took them about 10 years to fix this one ...

Post by Inicio | 2017-10-03 | 23:49:44

Post by Inicio | 2017-10-04 | 00:38:57

EDIT
Strange TWA and TWS

Now in zezo: 208 at 135 TWA, 14,5 TWS
Now in VR:: 208 at 118 TWA, 12,8 TWS

44N 59' 5"
8W 35�39"

(118 TWA is not a good wind angle with 12.8 knots)

Last night was the same thing

Post by M63 | 2017-10-04 | 00:40:54

Hello,

TWD is false by 20� to 25� since GFS12Z.

Post by zezo | 2017-10-04 | 00:41:31

Nothing strange. VR have not applied the last (two) GFS outpus, so the weather is stuck with the Tuesday noon forecast (GFS06z)

The actual timestamp of the wind schedule is
""Tue, 03 Oct 2017 14:20:04 GMT""

I was hoping they'd get in sync now with the GFS18z, but no such luck.

Post by Toppen | 2017-10-04 | 01:13:17

Is this correct? Does VR have the wrong wind speed since 6-12 hours? It looks like the "Raketa group" has been in 2 knots less wind for a long time now while the "SPEEDO group" has been in better wind... is this a new version of the "4 knots limit" where VR can choose to favour people of their choice? Has anyone pointed this out to VR?

Post by zezo | 2017-10-04 | 01:10:50

There is no correct way out of it. I could revert to their version of the data, but then when they get in sync our positions will be wrong for the new weather conditions. So i personally prefer to sail in the general direction suggested by the proper forecast.

Post by Toppen | 2017-10-04 | 01:18:51

What i meant was, how the h_ll can VR use wrong weather data... i'm not part of this race (other than with a spectator/guest boat) but this is not good... especially when part of the fleet has chosed to go the long way to get better wind and (again...) now it is the opposite, like the first two legs of the Zanzib... Has anyone seen posts about this on the forum?

Post by marcusbelgicus | 2017-10-04 | 20:09:50

They want to force us to use their weather cards!!!!! Otherwise we can use external source of data to get that info

Post by Inicio | 2017-10-04 | 01:25:20

For a while the wind is rising very fast ...

Post by Inicio | 2017-10-04 | 01:34:11

Now
Zezo: 209, 135 TWA, 14.9 knots
V R : 209, 122 TWA, 14.1 knots

Less gap

Post by marcop0l0 | 2017-10-04 | 01:55:58

Currently VR is running with a wrong date, 1 day in advance, so I imagine that VR is expecting file for the next day but these file cannot exist already so VR don't apply any change.

Post by Inicio | 2017-10-04 | 03:00:52

Now

Zezo: 210, 136 TWA, 15.8 kts
V R : 210, 131 TWA, 16.0 kts

Less gap. More speed.

Post by zezo | 2017-10-04 | 07:09:18

It's just a coincidence. They are still serving the data from yesterday.

The first file is https://static.virtualregatta.com/winds/live/20171003/06/021.wnd

Path says it all - 20171003/gfs06z

Hopefully someone will wake up today, go to the office, read their email and fix it for the today's 06z

Post by Inicio | 2017-10-04 | 07:36:56

OK.
Thanks

Post by Inicio | 2017-10-04 | 07:34:02

Now

Zezo: 218, 155 TWA, 16.9 kts
V R : 219, 155 TWA, 18.3 kts

No gap. More speed.

Post by Cyann | 2017-10-04 | 09:38:34

Hi,

As the data between you and VR are not the same, can we trust you and apply your strategy or the difference of winds make it false?

Regards

Post by zezo | 2017-10-04 | 12:38:37

It's hard to say. Depends to some extent on when VR get back in sync.

When they do the current routing will be closer to reality than their current forecast. But if they leave it this way long enough the router will be useless.

Post by Inicio | 2017-10-04 | 11:24:12

Is it possible that it is not a mistake?

Right now I have 20.6 knots of wind. I do not remember seeing this in the forecasts of yesterday ... Is it possible to manipulate global wind intensity in a forecast file ?

Maybe they want this regatta to finish sooner and keeping these winds going like this ... Today begins Clipper and on the 8th VOR ...

Meanwhile they have had time to activate the boat search box ...

Post by zezo | 2017-10-04 | 12:41:08

It's very unlikely, but not impossible that they did it on purpose.

If done to break the players using external routers - that won't work in the long run, because I (and every one else) can with some effort recreate their exact version of the wind field.

Post by meteo79niort | 2017-10-04 | 12:08:05

Cvetan, how do you read wind files .wnd ?

Post by zezo | 2017-10-04 | 12:30:20

I don't. What I mostly do is look at the URLs

I mean I can, but don't have to. They are GFS files encoded in specific way. There is a small error, but not big enough to matter (and I actually recreate it)

The content is 1-byte signed values for u/v wind components with 360x181 resolution (1-degree). But they are not linear mapping - values are proportional to the square root of the actual data. This gives better precision on the low side.

Post by zezo | 2017-10-04 | 12:33:12

What I'm also looking at in the last 24 hours is a file called references.bin. It's encrypted, but in the previous version was plain text and contained the mapping between time and the .wnd files

"export_ts": 1507040400,
"export_time": "2017-10-03T14:20:00+00:00",
"publish_ts": 1507040403,
"publish_time": "2017-10-03T14:20:03+00:00",
"start_ts": 1507032000,
"start_time": "2017-10-03T12:00:00+00:00",
"references": [
[{
"reference": "2017100306@6",
"reference_ts": 1507010400,
"valid_ts": 1507032000,
"valid_time": "2017-10-03T12:00:00+00:00",
"delta_ref": 6,
"delta": 0,
"avail_ts": 1507023004,
"avail_time": "2017-10-03T09:30:04+00:00",
"rel_path": "live/20171003/06/006.wnd"

Post by zezo | 2017-10-04 | 12:35:33

This file still has modification time -24 hours now (last-modified:Tue, 03 Oct 2017 14:20:04 GMT) , according to the http headers.

Post by Inicio | 2017-10-04 | 12:49:18

Now, I see the same TWD and TWS in Zezo and VR.

Post by zezo | 2017-10-04 | 12:53:25

Yep, they just got back in sync.

references.bin: last-modified: Wed, 04 Oct 2017 09:46:52 GMT

Post by Inicio | 2017-10-08 | 13:56:46

It seems that there is again a TWS TWD gap since the last forecast update.
Do you see the same thing?

Post by zezo | 2017-10-08 | 14:24:57

Thing is that for 3 hours VR seem to interpolate between two forecasts for the same point of time. Like GFS00+12 GFS6+6.

I use only one of them. So if there is a big difference between the two model outputs it shows (worst case around 11h UTC)

Post by ApolloSails | 2017-10-29 | 16:15:38

When can we see the next Mini Transat leg in the windplotter?

Post by zezo | 2017-10-29 | 16:50:14

Maybe later today. I'm using the day to organize the things a bit.

Post by ApolloSails | 2017-10-29 | 16:56:08

Thanks for the answer Cvetan, you are doing a great job for us all sailing enthusiasts. Returning with a small contribution to the development of both hardware and software for this purpose.

Post by zezo | 2017-10-29 | 17:19:14

Thanks.

I'll update all open races soon, maybe tomorrow. The code gets slightly different with every new race that includes new features (or new discovery is done about some game details)

I'm currently trying to get everything back in sync, then add some small features, do some testing and update the links.