The Weather Routing stops before reaching the destination

[rgleason]

Sean, I had been thinking something similar, where when a boat hits low or high winds and its polar has 0 that the boat would pause and not go anywhere during the time the wind is too high or too low. During that time a cross mark would be made on the optimal route and a 0 wind barb would be shown. This should be a check option I think. "Don't fail polar when TWS is out of range, just wait".

Also if there were a chance to show a yellow message when you hover over that point in the optimal route, which gives the duration of the pause and grib wind conditions (high or low).

Also, when the wind is too high for the polar, it is a pause or hove to, and there would be drift backwards at say 1/4 the speed of the wind. Maybe thats something to program later.

I have no idea if it would mess stuff up.

[rgleason]

Another thought I had was to put an equilateral triangle with the perpendular away from the start point, on the optimal route, when the grib file data runs out. With a yellow mouseovet message, "grib data has ended". To provide a visual clue to the user.

[joseph79]

Originally Posted by stelian

This really looks like a plugin version problem. Maybe ocpn_draw is too old ?

What is the version reported in the main opencpn configuration window, plugins tab ? Mine is 1.4 (well, compiled locally from git but I don't think it matters).

Dear Stelian, thanks a lot for your feedback...
I repeated the Routing several times.. sometimes the error appears, sometimes instead not.. I don't know..
The version of the plugin is the last one.. 1.4

Thanks again..
Joseph

[joseph79]

Originally Posted by rgleason

Have you updated ocpn_draw to current? Jon G recently updated it.

Dear RGleason, the version of the plugin is the last one 1.4,
The error sometimes appears and sometimes not.. I'll repeat many routings in order to test it..
thanks a lot.
Joseph

[did-g]

Originally Posted by boat_alexandra

Try adding 0.0 for both min and max windspeed direction, so add 0.0 for 150 degrees. It should now work.

Blank means no data. It will try to interpolate from other values in the polar if possible, but it never tries to extrapolate, at least not yet.

Since 0 is the lowest wind speed it cannot use the higher wind speeds to interpolate, so you would need to at least define 0.0 at 0 degrees, and 0.0 at 150 degrees. Now it could interpolate the other values.


Again, this is not interpolation but extrapolation. Unless you define that the boat goes zero speed at zero knots, it cannot interpolate values less that 6 knots for that polar.

Now maybe logically, we should make this adjustment, after all, most boats go no where with no wind, so if we are careful not to break polars that do have boat speeds at 0 wind (like motoring) it can work.

So what do you think? Assume zero boat speed at 0 knot of wind if the polar doesn't have a zero wind speed column? I think maybe it can work, but don't want to make a new problem.

Hi,
At least polar files with WR plugins should work, in the Med no wind or too much wind...

Moreover what most other routing softwares do? In my understanding these polar files format is a de facto standard; it would be nice if copying a polar working in an other software works with WR in a sensible way.

[rgleason]

Joseph, First thank you for perusing this, same for Stelian, it is essential to stamp out bugs.
Joseph, the guys are actively developing this plugin so there are frequent updates, check here

I am trying to replicate your problem to understand it better.
1. Do you know that you can add multiple polar files (which will span different wind ranges) and the best one will be picked automatically by the plugin?
2. Try making a new Boat file called "Example". Then "add" polars to it from the "Example" subdirectory. Add these polars:

Example-0-10.pol
Example-6-24.pol
Example-15-30.pol
Example-24-60.pol

The numbers are the true wind speed range TWS (You should read about this in the manual though!) Try to compute the routing. If it does not work, get it working! Make sure your grib dates match Use the second interval in the grib file please. If it then works remove the Example 24-60 and see if it runs completely. Then if it works remove 15-30 etc.

If the routing does not work, after working on it, upload the following files:
from the programdata/opencpn/plugin/weatherrouting directory:

weatherroutingconfiguration.xml
the grib file used

Sorry Joseph, I am catching up after being away sailing, I see you left two files below. I'll try them.

[rgleason]

I've run some testing here using a specific set of files.
Sometime Land Detect and Boundary avoidance are spotty and I haven't figured out why, but I got it working I think.

Try toggling Boundary properties and exclude include, to make sure it is set properly to exclude. Also make sure and toggle active inactive boundary. Also, if land detect and boundary are not working well, shorten the interval! It makes a big difference to have small baby steps, particularly in the area of islands and many objects to avoid. I took the interval down to 30 min, and even 15 min and it really helps. It takes longer, but the routines have an easier time figuring out the proper route.

This is not a simple unknowing push-button get results affair. You must learn how she works and think about what you are doing, and she'll perform for you. Think of it as a dance, give her good clear instructions and she'll be a your ballerina.

We will have to work on the spottyness, but I think wxrouting is getting better, take heart. A little more work and she'll be much better.

https://github.com/seandepagnier/wea..._pi/issues/195
https://github.com/seandepagnier/wea..._pi/issues/196
https://github.com/seandepagnier/wea..._pi/issues/194

[Moo]

Originally Posted by rgleason

Sean, I had been thinking something similar, where when a boat hits low or high winds and its polar has 0 that the boat would pause and not go anywhere during the time the wind is too high or too low. During that time a cross mark would be made on the optimal route and a 0 wind barb would be shown. This should be a check option I think. "Don't fail polar when TWS is out of range, just wait".

Also if there were a chance to show a yellow message when you hover over that point in the optimal route, which gives the duration of the pause and grib wind conditions (high or low).

Also, when the wind is too high for the polar, it is a pause or hove to, and there would be drift backwards at say 1/4 the speed of the wind. Maybe thats something to program later..

Showing zero knots through the water when there is no wind is a good idea; if there is a current GRIB loaded then COG and SOG should reflect the current.

Hove to drift is going to be very low nothing like 1/4 TWS (imagine drifiting at 12.5 knots in 50 knots!). This could be something that the user could enter for their own vessel and style. My boat tends to fore reach rather than heave too in a traditional sense; therefore I am thinking that a drift angle relative to TWD and drift speed could be entered by the user.

[rgleason]

Originally Posted by Moo

Hove to drift is going to be very low nothing like 1/4 TWS (imagine drifiting at 12.5 knots in 50 knots!).

Moo. Agreed! Hadn't thought it through.

[rgleason]

Land Detect. Dumb oversight. I had other charts on rather than the Outline GSHHG, as Pavel pointed out. GSHHG does not show any landmass in much of the Caribbean. Land Detect is working fine, and after initial boundary failure messages, it seems to be working too. (toggled, properties such as exclusion, inclusion, none, and then toggled active/inactive. Also made new boundaries that worked.)

[joseph79]

Originally Posted by rgleason

Joseph, First thank you for perusing this, same for Stelian, it is essential to stamp out bugs.
Joseph, the guys are actively developing this plugin so there are frequent updates, check here

I am trying to replicate your problem to understand it better.
1. Do you know that you can add multiple polar files (which will span different wind ranges) and the best one will be picked automatically by the plugin?
2. Try making a new Boat file called "Example". Then "add" polars to it from the "Example" subdirectory. Add these polars:

Example-0-10.pol
Example-6-24.pol
Example-15-30.pol
Example-24-60.pol

The numbers are the true wind speed range TWS (You should read about this in the manual though!) Try to compute the routing. If it does not work, get it working! Make sure your grib dates match Use the second interval in the grib file please. If it then works remove the Example 24-60 and see if it runs completely. Then if it works remove 15-30 etc.

If the routing does not work, after working on it, upload the following files:
from the programdata/opencpn/plugin/weatherrouting directory:

weatherroutingconfiguration.xml
the grib file used

Sorry Joseph, I am catching up after being away sailing, I see you left two files below. I'll try them.

Dear rgleason,
thanks a lot for your feedback and suggestions.
Just another question about polar,
please find attached my last polar, it seems work fine..
my question is:
is the wind data at 2ktns extrapolated from data at 0.5 and 6 ktns?
Best Regards.
Joseph

[nohal]

Originally Posted by joseph79

Dear rgleason,
thanks a lot for your feedback and suggestions.
Just another question about polar,
please find attached my last polar, it seems work fine..
my question is:
is the wind data at 2ktns extrapolated from data at 0.5 and 6 ktns?
Best Regards.
Joseph

Joseph...

No, in case of the polar on your picture the data at 2 knts are interpolated from data at 0.5 and 4 knts.

Extrapolate = Guess the data completely out of our known range (Tends to be more inaccurate. Usually worse the further you are from the end of the known range.)

Interpolate = Guess the data between 2 values in our known range (Generally tends to be less inaccurate than extrapolation as it "autocorrects" as you pass the next known value where it is "exactly right")

What you did is take the responsibility of turning the extrapolation into interpolation by extending the known range close to no wind/no speed. Some other tools do similar stuff automatically as you know. And yes, implementation of logic this trivial can be made automatic in the WR plugin as well (Which will not make this logic more correct)

Pavel

[joseph79]

Originally Posted by nohal

Joseph...

No, in case of the polar on your picture the data at 2 knts are interpolated from data at 0.5 and 4 knts.

Extrapolate = Guess the data completely out of our known range (Tends to be more inaccurate. Usually worse the further you are from the end of the known range.)

Interpolate = Guess the data between 2 values in our known range (Generally tends to be less inaccurate than extrapolation as it "autocorrects" as you pass the next known value where it is "exactly right")

What you did is take the responsibility of turning the extrapolation into interpolation by extending the known range close to no wind/no speed. Some other tools do similar stuff automatically as you know. And yes, implementation of logic this trivial can be made automatic in the WR plugin as well (Which will not make this logic more correct)

Pavel

Hello Nohal,
thanks a lot for your promt feedback..
Just another question..
is it possible on OpenCPN to show the ISOROUTE, that is, the time sensitivity of the Weather Routing performed?

Kind regards.
Joseph

[nohal]

Originally Posted by joseph79

Hello Nohal,
thanks a lot for your promt feedback..
Just another question..
is it possible on OpenCPN to show the ISOROUTE, that is, the time sensitivity of the Weather Routing performed?

Kind regards.
Joseph

I honestly have no idea what you talk about.
Do you mean if there is exactly same functionality of what Adrena describes as "IsoRoute: drawing a zone on the map that will get you to the finish in the quickest time possible, relative to the optimum route. This feature means that Adrena recognizes that there is sometimes more than one route to the finish." (Which I also don't understand much)?

Pavel

[rgleason]

Is it possible on OpenCPN to show the ISOROUTE, that is, the time sensitivity of the Weather Routing performed?

I assume this is for planning purposes, similar to "Departure Planning" where multiple start intervals between two date/times are run. Can you explain in greater detail what Isoroute is? a definition or something? Also where do you get this term?

You can do departure planning by duplicating a configuration and changing the start date/time however many times you want. Then highlight all your configurations and click Compute, and they will all be computed concurrently using process threads. Then check out the resullts and pick your weather window.

BTW The plugin uses the isochrone method for calculations.

Here are some screenshots using your polar, showing how Sean has enabled "interpolation" as Pavel has described. First you add some TWS columns in the Edit Polar > Dimension Tab, then you just fill in the start and end values in the Edit Polar > Grid Tab and the rest of the values get interpolated.

Also, note that it does not make too much difference if you have TWS=0 column or TWA=0 row, the polar diagram remains the same. Indeed in an earlier version of the plugin we needed to remove TWA=0 rows. It appears the plugin is more forgiving about this now.