Zezo forum:

Post by Sailkap | 2009-11-19 | 22:08:59

I noticed that the winddata (speed and angle) don�t is accurate according to the game... can you pls corrct?

24 Comments

Post by Belladonna | 2009-11-19 | 22:13:52

Hi Cvetan,

I was just posting a message on the TJV topic when I saw this one. Same subject, What's happening ?

Bernard

Post by zezo | 2009-11-19 | 22:32:30

I just got home.

According to the log files the GRIB update went without error.

So either MP missed an update, or they changed the forecast times. We'll know tomorrow.

Post by Sailkap | 2009-11-19 | 22:57:53

Don�t you make a reload of forecast at 22 o�clock (GMT+1)?
Won�t that perhaps correct the mishaps?

Post by Sailkap | 2009-11-19 | 23:13:35

Unfortunately the answer was no... so now it�s time for some own old calculations...:) The big ? is can we relay on the forecasts?

Post by dids74 | 2009-11-20 | 01:40:21

what i understand is that MP is using the forecast calculated at 11.30 am for the time 8pm, instead of using as usual the forecast calculated at 5.30 pm for the time 8pm( local time in Paris). I am not even sure that this is consistent with the forecast MP gives in the game interface.

Post by dids74 | 2009-11-20 | 10:35:58

this morning MP uses the wind forecasts calculated at midnight for the time 8 am (Paris time)instead of forecast 5.30 am for time 11 am as previously done. ZEZO uses midnight forecast for the time 11am.

Post by zezo | 2009-11-20 | 12:42:02

Yes. The current weather is indeed GFS18Z+12 instead of GFS0Z+9. The morning 12-h forecast is 18Z+24

I've updated it manually, and calculations should correspond to the game, but the displayed winds will be off.

The same will probably be true for the next few days too.

Post by Hieronymous | 2009-11-20 | 13:43:40

Hi zezo,
Why wouldn't you take the weather at time T on the MP resources :
http://jacquesvabre.virtualregatta.com/resources/winds/meteo_long_lat.xml
(Where long is the longitude and lat is the latitude of a square of 10 x 10)?
So you could have the same weather as MP at 8h am and pm and for the forecast you keep the log files GRIB ...
What do you think about this idea ?
Regards
(Excuse my english, I'm french .... ;) )

Post by zezo | 2009-11-20 | 14:04:04

You have a point, but fortunately those discrepancies happen very rarely - once in few months and that's not enough to lose the advantages of direct grib files.

Taking the weather from the original source can happen earlier. If the current changes persist it will make huge difference - you will know what will happen 8 hours in advance, but even the 1 or 2 hours in the normal mode of operation can gain you some places.

The forecasts at the game site are also incorrect - they don't mach the point of time of the actual weather that's applied. Few of the best players learned that the hard way during the Istanbul Europa race.

I'll keep the current weather in sync manually in the next few days until we see if it's just a glitch or it will stay this way.

Post by Hieronymous | 2009-11-20 | 14:33:52

So I understand that the original data is better than the MP data for the forecast but it was just an idea for avoid this situation without too much work for you !!
Anyway you have done an incredible tool, the best of all in my opinion (better than MaxSea which don't take into account the different sails during the sailing prediction). I've done an Excel sheet with different calculations but your job is simple, easy and especially right !!!
What a pity that during the Vendee Globe I didn't get it, maybe I would have done better than 173 rd !!
Go ahead ....

Post by Belladonna | 2009-11-20 | 14:54:15

Congratulations Cvetan, you have resolved the problem, or at least the main part of it, in a very short term.
Thanks for your help :-)

Post by Sailkap | 2009-11-20 | 17:36:51

Does that mean the forecasts are true or false?

Post by zezo | 2009-11-20 | 18:31:19

You have to check every time. I can change the algorithm but then MP can change it back, so you never know.

Please give me 10 minutes after the updates to fix possible differences.

Post by Sailkap | 2009-11-20 | 20:43:57

ofcourse, take you�re time... thanks!!

Post by boulpat | 2009-11-20 | 18:57:46

Merci, le jeu retrouve son charme...!!!
jean-paul.

Post by dids74 | 2009-11-20 | 20:53:23

hello cvetan,
I think you are right to keep in sync manually.
one guy in the game gets the forecasts from a different source and noticed the same discripancies, maybe because they get the files from the same supplier, this is to say, not directly.
In that case, everything could get back to normal very soon...