Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 03-12-2012, 13:13   #271
Registered User
 
rgleason's Avatar

Join Date: Mar 2012
Location: Boston, MA
Boat: 1981 Bristol 32 Sloop
Posts: 9,382
Re: VENDÉE GLOBE round the world race

Thank you Maitai.

Quote:
rgleason...
One other question. In Route Settings > Autopilot "Load preselected POI's" Button. How do you use that option? How to I preselect a POI? Do I copy it? Then Paste into the window or hit "Load preselected POI" button?
Quote:
maitai....
That was a request by vlm committee, but it is not very useful imo. In fact you can right-click on a poi belonging to a route and choose "preselect for pilototo" or something like that. Then only these POIs will be sent to pilototo.

The interval parameter in the route's details is just to filter the list, for instance one hour by one hour, instead of 5/5 minutes. [Rick -It does not affect the actual route in any way, just the number of points that show in the list.]

"Reckoning" (8) is the length of your esteem. The small checkbox close to it has an tooltip help text. I can explain further if you need.
"The length of your esteem" - Wiki Draw a QtVlm Grib Esteem QtVlm grib esteem - VlmWiki - Is an "esteem" [or Estimation] a <Route> or <Routing> which uses Isochrones to develop the shortest ETA (estimated time of arrival)? The "length" is in Days?

Hover over "vacs" check box in upper menu bar "If this option is checked esteem calculation calculates boat speed at next vacation, otherwise it uses boat speed as given by VLM"
__________________

__________________
rgleason is offline   Reply With Quote
Old 03-12-2012, 13:24   #272
Registered User
 
rgleason's Avatar

Join Date: Mar 2012
Location: Boston, MA
Boat: 1981 Bristol 32 Sloop
Posts: 9,382
Re: VENDÉE GLOBE round the world race

Ah, I found this on the Wiki Routing with qtVlm
Routing with qtVlm - VlmWiki
  • Wake angle, exploration factor
    • At each calculation loop, some possible routes are discarded, in order to limit the calculation time.
    • The wake angle parameter will discard the points that are in the wake of more advanced points, while the exploration factor defines the number of extra points to keep.
    • In other words, a smaller wake angle and a bigger exploration factor will result in more possibilities explored, but a longer calculation time.
  • Alternate routes: This option will try to detect the main alternatives to the best route. It analyses all the points at 75% of the distance and will show the n routes which arrive faster, if their way is at least x % differents from each other (n and x are in advanced options).
  • Minimum/maximum wind, upWind/downWind will force the routage to avoid these zones in the Grib.
  • Auto Zoom allows you to fine tune the automatic zooming, depending on your screen geometry.
Sorry, Maitai.. It is all there!



See the Inversed Isochrones explanation at the bottom with an example image. The "inversed isochrone" is a solution to the old Downeast Maine joke: "Ya can't git there from here." -Starting from the finish point, what are the areas of sailing that will most likely get you to the finish fastest.

Quote:
From wiki...
If the option "convert to route" has not been selected, you can after the calculation edit the routing (menu routing->edit a routing) and ask for the inversed isochrons, which means recalculating the routing from the arrival point and time backward to the start. Note that for this option to be available the isochron's duration must be the same for less and more than 24 hours. See after for more details on this and how to use it.
To do inverse routing set the 24 hour and more than 24 hours to the same duration!! otherwise there is an error dialogue that it cant do it.

Main English Wiki
http://wiki.virtual-loup-de-mer.org/index.php/QtVlm/en
__________________

__________________
rgleason is offline   Reply With Quote
Old 03-12-2012, 13:41   #273
Registered User
 
rgleason's Avatar

Join Date: Mar 2012
Location: Boston, MA
Boat: 1981 Bristol 32 Sloop
Posts: 9,382
Re: VENDÉE GLOBE round the world race

Meteo Faxes - A new world of interpretation - check out the overlay in QtVlm at the bottom "Comparing a Grib and a Meteo-Fax". I am looking for meteo faxes of the Southern Ocean right now. NOAA has them for the North Atlantic and Pacific.
QtVlm meteo faxes - VlmWiki
__________________
rgleason is offline   Reply With Quote
Old 03-12-2012, 13:51   #274
Registered User
 
rgleason's Avatar

Join Date: Mar 2012
Location: Boston, MA
Boat: 1981 Bristol 32 Sloop
Posts: 9,382
Re: VENDÉE GLOBE round the world race

Southern Ocean -Sailing Weather - Marine Weather Forecasts for Sailors and Adventurers - PassageWeather Menu on left ,Click on Indian Ocean / Southern Indian Ocean - No analysis, animation of Wind grib, Pressure and Waves
Does anyone have a good source?

NOAA does the Northern Half Ocean Prediction Center
__________________
rgleason is offline   Reply With Quote
Old 04-12-2012, 01:45   #275
Registered User

Join Date: Jan 2012
Posts: 450
Re: VENDÉE GLOBE round the world race

From VLM race committee:


Icegate Amsterdam will NOT be created and Icegate West Australia will NOT be moved!

But all remaining Icegates after WP7: East Australia, New Zealand, West Pacific and East Pacific will be moved!



Porte Australie Est / East Australian Gate 50°00 S 136°00 E - 147°00 E >>> 45°00 S 135°00 E - 145°00 E
__________________
maitai is offline   Reply With Quote
Old 04-12-2012, 02:10   #276
Registered User

Join Date: Jan 2012
Posts: 450
Re: VENDÉE GLOBE round the world race

Quote:
Originally Posted by rattus View Post
I get what you're saying, but sometimes you have to backtrack in order to find an optimal route. 2 questions:

1) Any comment on my observation that the exploration coefficient, alternate routes values and exploration angles seemed to have no effect?

2) In which file is the code for the router? I have a few ideas...
1) It does have an effect. The routing keep more or less the same number of isopoints at each pass. Increasing this parameter just increase the number of points kept (I usually leave it with the default value on my tablet because it's a slow machine. On a stronger PC I usually put something around 70. The other param have an effect too. Scanning angle is limited to 180 (179, even), as said before.

2) Man it's open source! So if you improve on the algo please let us know The routing class is in routage.cpp and routage.h.
__________________
maitai is offline   Reply With Quote
Old 05-12-2012, 10:47   #277
Registered User
 
biltong's Avatar

Join Date: Nov 2009
Location: Knysna, South Africa
Boat: Sadler 26
Posts: 138
Re: VENDÉE GLOBE round the world race

I keep on getting a notification that I have been sailing with a BAD sail. Also, If I try to use a spinnaker it says that my boat has not been saved. Does anyone have any ideas as to why?
Much appreciated.
pS this is the virtual race of course.
__________________
Arguing with a fool is two fools arguing
biltong is offline   Reply With Quote
Old 06-12-2012, 09:20   #278
Registered User
 
rgleason's Avatar

Join Date: Mar 2012
Location: Boston, MA
Boat: 1981 Bristol 32 Sloop
Posts: 9,382
Re: VENDÉE GLOBE round the world race

Long <Routing> with multiple Pivots [Cursor define an alternate Routing that is highlighted, then Right Mouse Button, "Create Pivot Point"] suggestions:
1. I use a recent Saildocs Grib close to the time of the VLM Gribs for long routing.
2. Just get a pivot that is reasonably close, this "non-simplifiable" POI can be moved and adjusted later.
3. After creating the long Routing, convert it to a <Route> to adjust the "Non-simplifiable" POI.
4. In Route Edit, uncheck the "Hide intermediate POI" for the long route. Close.
5. In the chart right click on Green POI boxes in the area where you created the Pivot and Pick "Edit" that it has "Not Simplifiable" checked. If it is not checked close the dialogue and continue searching POI in that area. Once the Pivot point "Not Simplifiable" POI is found you can move it by hovering over it and pressing "Shift + Left Mouse Button". Move the POI to the location you want and release Left mouse button first.
6. If you find you have extraneous "non-simplifiable" POI you can uncheck them or delete them.
7. A <Route> can be Simplified and Optimized multiple times with a new current GRIB. It cannot have VLM-VMG checked however.
8. VLM-VMG checked Routes. You must uncheck VLM-VMG run your new optimization, then recheck it, apply, wait to respond Yes to the new change in route, then Load the new POI and send to the autopilot.
9. It is helpful to understand the weather and wind conditions while setting Pivot Points. I use the Time controls for that purpose, for example to see which end of an Ice Gate is best.

Note: These long Gribs are so far out, they change a lot over time, but they can affect short term strategy. In the end it is the single legs that really count.
__________________
rgleason is offline   Reply With Quote
Old 06-12-2012, 15:00   #279
Registered User
 
rgleason's Avatar

Join Date: Mar 2012
Location: Boston, MA
Boat: 1981 Bristol 32 Sloop
Posts: 9,382
Re: VENDÉE GLOBE round the world race

Caution Note about Optimization of Routes that have been simplified.
When Routings have been converted to Routes and Simplified, they can be optimized using newer gribs and the route will be updated, however if the grib has changed significantly enough, the Route will not have intermediate points which will allow more subtle and faster shortcuts with faster ETA. Therefore sometimes it is better to Create a New Routing, Convert, then Simplify and Optimize. You will find the course is slightly different, with perhaps some additional intermediate tacks, although the route may be generally similar. Maitai may have a comment on this.

The point is, that without some Intermediate POI's in a given leg, the re-Optimization does not know enough to put in an additional intermediate POI if it is needed, thus it is better to start over with Creation of a new Routing.
__________________
rgleason is offline   Reply With Quote
Old 07-12-2012, 18:12   #280
Registered User
 
rgleason's Avatar

Join Date: Mar 2012
Location: Boston, MA
Boat: 1981 Bristol 32 Sloop
Posts: 9,382
Re: VENDÉE GLOBE round the world race

Quote:
I keep on getting a notification that I have been sailing with a BAD sail. Also, If I try to use a spinnaker it says that my boat has not been saved. Does anyone have any ideas as to why?
Is this spam or a joke? It has never happened to me. Perhaps you can explain further?
__________________
rgleason is offline   Reply With Quote
Old 07-12-2012, 22:29   #281
Registered User
 
biltong's Avatar

Join Date: Nov 2009
Location: Knysna, South Africa
Boat: Sadler 26
Posts: 138
Re: VENDÉE GLOBE round the world race

Not Spam. I contacted Manyplayers.com and they sorted it out for me.
__________________
Arguing with a fool is two fools arguing
biltong is offline   Reply With Quote
Old 08-12-2012, 06:03   #282
Registered User
 
rgleason's Avatar

Join Date: Mar 2012
Location: Boston, MA
Boat: 1981 Bristol 32 Sloop
Posts: 9,382
Re: VENDÉE GLOBE round the world race

Biltong, I feel like I'm sailing with a dirty bottom, maybe even a bad boat as I can't seem to break through 200, the good news is Maitai is 17 and Kirke is 54. Perhaps my problem is I refuse to get up at midnight to download a new grib. I have resolved that this race is not going to dictate my life!

I notice that the Vendee Spectator site only shows about 500 boats, is that due to technical issues?
__________________
rgleason is offline   Reply With Quote
Old 08-12-2012, 06:07   #283
Registered User
 
rgleason's Avatar

Join Date: Mar 2012
Location: Boston, MA
Boat: 1981 Bristol 32 Sloop
Posts: 9,382
Re: VENDÉE GLOBE round the world race

Gribs
I've concluded it is best to do current and next leg routes with VLM which are exactly what the VLM server uses, the longer Saildocs Gribs, differ in small ways depending on when you download those. Longer term routing with multiple pivot points is possible with Saildocs.
__________________
rgleason is offline   Reply With Quote
Old 08-12-2012, 06:58   #284
Registered User
 
rgleason's Avatar

Join Date: Mar 2012
Location: Boston, MA
Boat: 1981 Bristol 32 Sloop
Posts: 9,382
Re: VENDÉE GLOBE round the world race

Above I meant "VLM Gribs".

Suggestion for Long Distance "Multiple Pivot Point Routes". After the route has gotten stale/old (several cycles of Grib - How many is unkown) under Edit Route you can "Optimize" again. Then take down the ETA. Then move one of the Pivot Points and "Optimize" again. Compare ETA.

This avoids having to recreate the Multiple Pivot Route, but when the route gets really stale it is probably better to re create it.
__________________
rgleason is offline   Reply With Quote
Old 08-12-2012, 07:12   #285
Registered User
 
rgleason's Avatar

Join Date: Mar 2012
Location: Boston, MA
Boat: 1981 Bristol 32 Sloop
Posts: 9,382
Re: VENDÉE GLOBE round the world race

Using this technique, you can determine which end of an Ice gate is favored, or if the middle of the gate is favored, for example, under the active grib prediction. Of course these gates are a long distance away and the prediction may change.
__________________

__________________
rgleason is offline   Reply With Quote
Reply

Tags
race

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off




Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 14:52.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.