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Old 17-11-2012, 07:43   #151
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Re: VENDÉE GLOBE round the world race

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Originally Posted by rgleason View Post
Is that why I am doing this? To learn more, get that sixth sense? Become a better sailor? I've got to start understanding the weather better, start tracking lows and highs which make the wind. As you can tell I'm looking for reasons to continue this entire race...and find a way to do it without it occupying too much of the day. Any suggestions? ....I need to keep 8 hours for other work, is a start. Check in in the middle.

Maybe it's 4 hour or 6 hour shifts and no more than 15 minutes on routing. -What to do at night? Anyway my dear mate is asking why I am so far behind now..54...
IMHO it is a waste of time unless you have access to comparable wx sources in your boat while sailing.

Just following the real thing on the tracker and watching how they anticipate and react to the rolling wx will teach you all you want to know about where the wind blows and how to use it (that is to say for speed, which may differ dramatically from using the wx for comfort and safety).

Remember wave action is not allowed for. And in the real world wave action may and often will determine the cruising boat's track.

b.
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Old 17-11-2012, 08:34   #152
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Re: VENDÉE GLOBE round the world race

It's not that simple. I can and will add waves in the routing, it's almost done in the "dev" version.

In VLM everything is more simple. No waves, no Currents (note the "C", lol). Just wind and polar. Still it's very difficult... Nothing to do with having access to wx, we do have full access to that. I am a VLM admin and programmer so I am supposed to know.

It takes more than just a pure math approach, and that's why we love it. From what I know real sailing is like that too.
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Old 17-11-2012, 08:56   #153
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Re: VENDÉE GLOBE round the world race

Good Points:
Wave action, current, comfort, access to same data while on boat. Nevertheless, it helps to hone certain skills and become more familiar with the factors involved, including weather.
Idea: Have a Pressure Isobar or simple grib overlay on the Spectator Vendee Globe Guest Map with option to cycle the time (without moving the boats)


qtVlm - Route Optimization Program


Use of Routes and Routing:

Make a Routing

Start by making a Routing from the your boat to a particular POI that you have placed on the current grib (cursor on the spot and use right mouse button "place new mark")

Routing Explanation A "Routing" is different than a "Route". A "Routing" is a good route from the boat (or POI) to a POI/Mark. Routings show "isochrones" which indicate lines of identical sailing time. These are similar to isobars (shows lines of same pressure) but for sailing time. You will see "isochrones" that are close together, this means that sailing there is very slow (often caused by no or little wind). Conversely, if the isochrones are far apart you are sailing faster in heavier winds. A "Routing" creates a good route optimization and shows the isochrones from the boat or the starting location. It is very important to select good destination points, by thinking about what the winds and weather is likely to do afterwards. It is helpful to study multiple "Routing"s. Once you have a "Routing" you like, it is time to convert it into a "Route". Pick the "Convert to routing" check box in the Routing dialogue box.

Convert a Routing to a Route Done in the Routing Dialogue box. Check the "Convert to Route" box. This is the best way and only way to get a route unless you have exported one and then import it again. When you convert a Routing to a Route the program will ask if you want the newly converted route to be from the Boat or from a POI. If you select the route to be from a POI, the route can then be Frozen (see below). If you select the route to be from the boat, the route will follow the boat around as it moves, and you will continue to be able to optimize and simplify that route when you download and update new grib files.

Optimize a Route Check the box in the Route Dialogue and watch the program cycle through an optimization.

Simplify a Route Check the box in the Route Dialogue after you have optimized the route, to simplify and reduce the number of Intermediate POI's used. Why is this necessary? Because at some point you will be sending the list of waypoints to the "Autopilot" and the Autopilot only accepts six or seven intermediate waypoint instructions. Also it is often better to let the optimization between intermediate POI or waypoints occur in accord with how the actual winds blow. Fewer waypoints allow this to happen.

Freezing a Route- The Route must start from a POI (and end at a POI) and not be on VB-VLM. Routes from point to point can be frozen. Freezing the route stores all time and waypoint information for the last optimization. As you cycle through time the position will be shown, but it is for a previous (not current) grib file. If you uncheck a frozen route, and try to optimize it, it will complain and the route will probably disappear. Don't do this. You can hide and unhide frozen routes or export them.

Hide and Unhide a Route
- Useful to identify a Route (you can also use hover) or to clean up the screen. Often I find myself eventually deleting hidden routes. It would be helpful to have the delete route option show if a route is (hidden).

Routes from boats (rather than waypoints) to POI or points can be re-run optimized/simplified with a newly download up to date grib. This is a shortcut if you are keeping the destination point the same. Sometimes the weather has changed enough that it is wise to review weather, set a new point and create a new Routing and convert that. But this a a way to save time.

Export a Route - Simply save a route to a file (csv, txt, etc) Asks for POI or Detail.
Import a Route - Retrieve an older route.

Marks/POI It is a good idea to keep your POI clean and simple by deleting ones that are not needed. It would be nice to have a POI popup that allows you to highlight the POI and show the location, then allow a delete.

I hope this helps others who are interested in learning the program. Maitai may be correcting some of this because he's the authority.
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Old 17-11-2012, 09:51   #154
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Re: VENDÉE GLOBE round the world race

All good mate. Should go to the wiki/en

FYI another race is starting on sunday, with the same boat's polar (imoca). Following a real one too. Will last around 10/11 days.

Real event here Event Information for World Cruising Club: ARC

I'll be in
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Old 17-11-2012, 10:21   #155
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Re: VENDÉE GLOBE round the world race

Maitai, should I try to edit the wiki? I did not know if that would be ok, never have done that, also I wanted to be sure description was ok. Can snap shots be uploaded?

Quote:
...have a Routing and would like to see the lat/longs, courses, boat speed, & winds along the routing ...convert your routing into a route. Then you can go route->edit and see the route's details tab, or route->edit and check "display data from roadbook at grib date" option, to see all this while you change the grib's date.
Quote:
....option to display wind's strength along the routing, ...edit routing, uncheck "see Isochrons", and check "Color TWS between isos" instead.
[quote]
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Old 17-11-2012, 11:16   #156
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Re: VENDÉE GLOBE round the world race

No problems for editing the wiki, it is maintained by users only, not us developpers (or very little). Others will correct you if you are wrong (which is not the case imo). Uploading picts is ok too.
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Old 17-11-2012, 16:52   #157
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Re: VENDÉE GLOBE round the world race

Hi maitai,
is ther a problem with the vlm server ?
i cannot access to race at the moment
Hartmut
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Old 17-11-2012, 18:27   #158
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Re: VENDÉE GLOBE round the world race

Yes it seems the server is down... It will come back.
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Old 17-11-2012, 19:54   #159
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Re: VENDÉE GLOBE round the world race

Maitai:
Quote:
FYI another race is starting on sunday, with the same boat's polar (imoca). Following a real one too. Will last around 10/11 days.

Real event here Event Information for World Cruising Club: ARC
Thanks, I'll check it out when site comes back. Have been talking about doing Arc 2014 Spring to Azores, Spain or England with a friend on his larger boat.
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Old 18-11-2012, 00:55   #160
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Re: VENDÉE GLOBE round the world race

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Originally Posted by maitai View Post
Yes it seems the server is down... It will come back.
Thanks for information,
any idea when will the server be accessable again and how about the ships,
are they still running on the programmed course ?
Hartmut
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Old 18-11-2012, 01:21   #161
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Re: VENDÉE GLOBE round the world race

In fact it appears there is no more power at the server's location. Not much we can do... We are waiting for the provider to do something and restart... Should not be long now.
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Old 18-11-2012, 05:23   #162
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Re: VENDÉE GLOBE round the world race

Maitai - While there is no server or power for it, perhaps you could give us the grib update schedule in GMT or where to find this information? I hope the server can calculate fast enough once it gets up and running and that peoples routes are long enough. Did you have a power event in France?

Grib Update Schedule and accuracy

Quote:
As for the boat not following the route, each time there is an update of grib in VLM your route is not precise anymore. Since this it happening every 6 hours there is a big chance you were sleeping at one point
Quote:
In practice, if you know you will miss a [grib] meteo update, prepare the route a bit differently, and don't sail too close to the rocks, or leave some security distance from the gates.
Quote:
If you don't miss a meteo update and download a fresh grib each time, then the route is 100% accurate (maybe not the best, but what it shows is what the boat will do).
Quote:
Using qtVlm together with VLM you get exactly the same grib, interpolation algo for winds and polars, etc. Which is quite normal since it's made by the same team, and VLM/qtVLM are openSource anyway
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Old 18-11-2012, 06:06   #163
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Re: VENDÉE GLOBE round the world race

The problem is no power at the computer room. Normally (well this happened once, some 4 years ago), we make a big vac and let's go. This time the problem is more serious and we are evaluating what to do when it will restart. Quite probably every one will stay in the same position (which is not perfect, but nothing is perfect in fact)

We are still waiting for the supplier to fix the hardware... Sorry for that but you have also to consider this is a free service, we do not have the money to pay for full redondancy and such.

Bad feelings though.
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Old 18-11-2012, 06:19   #164
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Re: VENDÉE GLOBE round the world race

Maitai's words paraphrased for the Wiki

Difference between a Route and a Routing:


The two primary tools for optimal routes are Routing and Routes. Normally, after download of a current Grib file, you Create a Routing from your boat to a Mark or POI that you have created previously. Then from the Edit Routing dialogue box you can check Convert to a Route to do more detailed optimization and simplification.

Routing

The Routing will calculate the best path from arrival to start based on your polar and the grib, using isochrons method. You can force it to avoid certain zones by putting Barriers on the map, but this is normally not needed. Before a routing is converted in a route, you can also generate "child-routings" or alternative routes, by Creating a Pivot on one of the isochrone points (Right click on the point and select).

Route
To Simplify and Optimize a path to a POI, the Routing is converted to a Route by checking Convert to a Route in the Edit Routing dialogue box.

Simplification: (Check in Edit Route dialogue box)
Routings have one Intermediate POI at each isochrone crossing which require Simplification in order to Send a short list of 6 POI to the Autopilot (instructions uploaded to the server). The Simplification process will remove all POIs that do not improve the ETA, (typically aligned POIs are often not needed).

Optimization: (Check in Edit Route dialogue Box)
Then eventually you can optimize the route. Basically this process will try to reposition the POIs in better locations, because the routing process only looks at fix step (one hour), so it is understandable that a point might be better placed in between 2 isochrones. This is perfectionism, and IRL (in real life - actually sailing) not really useful, because the grib is not precise enough, however it is very useful in Virtual Racing (VLM), because the grib is of course 100% accurate in that case.
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Old 18-11-2012, 06:22   #165
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Re: VENDÉE GLOBE round the world race

Server is working! pgen still leads. The spectator website works. I can complete the startup of qtVLM, but the WP Gates and routes don't work, nor does Autopilot. Although the interrmediate points of routes seems to be there.
Will try later. Hartmut and Rick seem to be pretty close, with Frogeater is 137 at the head of this group and Maitai should be set up for a nice sail around the low.

Now I see these results are not right. I am further behind Hartmut than that!
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