The Weather Routing stops before reaching the destination

[joseph79]

Originally Posted by stelian

Joseph, it looks like these are not the correct files, WeatherRoutingConfiguration.xml should contain some information about your route (starting from Italy as I see in your screenshot), but the file you attached contains the default routes (canaries, Lizard, Provincetown etc)

Hi Stelian, thanks for your answer..

before starting the routing ( Compute) I set the start point and the end point by right cick on the map - Weather Route Position and after that I see the starting point and the endind point on the Weather Routing configuration ..
Effectively, now I see the WeatherRoutingConfiguration content and I don't see these points..
I don't know... mybe on the procedure that I'm following to setup the routing there is something wrong..

thanks a lot..
Joseph

[seandepagnier]

Again, it is pretty clear that you used a polar file that doesn't define boat speeds below 6 knots of wind. So it is the reason the routing stops when the wind drops below this level. I suggest you try many different polars and be sure you use one which defines a boat speeds in the winds defined in the grib used.

If you think the plugin is in error we can somehow fix it, but so far from what I have seen the plugin is working exactly as I designed it. You would have to suggest what it should actually do, and how, and I can make it do that if it makes sense.

If you want more feedback, you must post the correct WeatherRoutingConfiguration.xml that you used, not the default one which is in a different directory.

[joseph79]

Originally Posted by boat_alexandra

Again, it is pretty clear that you used a polar file that doesn't define boat speeds below 6 knots of wind. So it is the reason the routing stops when the wind drops below this level. I suggest you try many different polars and be sure you use one which defines a boat speeds in the winds defined in the grib used.

If you think the plugin is in error we can somehow fix it, but so far from what I have seen the plugin is working exactly as I designed it. You would have to suggest what it should actually do, and how, and I can make it do that if it makes sense.

If you want more feedback, you must post the correct WeatherRoutingConfiguration.xml that you used, not the default one which is in a different directory.

Hello Alexandra..,thanks a lot for your prompt feedback and support.. Within two hours I'll post the correct configuration file.. Regarding the polar, I have some doubt.. I'm coming from Expedition and Adrena and I never faced with a similar problem.. General the minimum win speed of the polar is 6 ktns, lower than this value the software interpolates..I can have also a polar with a minimum wind speed of 3 ktns but the wind may be 2ktns..and so on...without interpolation may be always a condition in which the routing stops for this reason...
Anyway I'll post you the correct configuration as soon as possible.. Thanks a lot...
Joseph

[rgleason]

Try adding all the example polars the numbers at the end reprsent trie wind speed tws

[joseph79]

Originally Posted by boat_alexandra

Again, it is pretty clear that you used a polar file that doesn't define boat speeds below 6 knots of wind. So it is the reason the routing stops when the wind drops below this level. I suggest you try many different polars and be sure you use one which defines a boat speeds in the winds defined in the grib used.

If you think the plugin is in error we can somehow fix it, but so far from what I have seen the plugin is working exactly as I designed it. You would have to suggest what it should actually do, and how, and I can make it do that if it makes sense.

If you want more feedback, you must post the correct WeatherRoutingConfiguration.xml that you used, not the default one which is in a different directory.

Dear Alexandra,
which is the correct path of the current file WeatherRoutingConfiguration.xml that I' Using in order to post the correct one?
Regards.
Joseph

[seandepagnier]

Originally Posted by joseph79

Dear Alexandra,
which is the correct path of the current file WeatherRoutingConfiguration.xml that I' Using in order to post the correct one?
Regards.
Joseph

It's difficult for me to say if you are not using linux, but for linux it's in ~/.opencpn/plugins/weather_routing

Alternately you can Select File->Save from the menu, I hope this helps.

Originally Posted by joseph79

Hello Alexandra..,thanks a lot for your prompt feedback and support.. Within two hours I'll post the correct configuration file.. Regarding the polar, I have some doubt.. I'm coming from Expedition and Adrena and I never faced

Thank you for trying free software.

with a similar problem.. General the minimum win speed of the polar is 6 ktns, lower than this value the software interpolates..I can have also a polar with a minimum wind

You do realize that most boats don't behave linearly for wind speed, at least in ocean waves, and especially not at the lowest wind speeds.

This is not interpolation. The plugin does interpolate. What you are describing is extrapolation, and it is dangerous to make these assumptions. The same argument was made for high wind speeds, and it just isn't how boats sail, even if it makes your routing work.

If you want this and it is your intention, then just add a 0.0 boat speed for 0 wind speed column to the polar for all wind speed directions. Don't use "0" because this is interpreted as "not possible". I know this is also very confusing. It would allow you even to avoid sailing against the wind at a higher wind speed, or even dead down wind in light wind which might be very useful, so it's a feature as well.

We recently had a debate, please read about it to continue the discussion:

https://github.com/seandepagnier/wea..._pi/issues/126

speed of 3 ktns but the wind may be 2ktns..and so on...without interpolation may be always a condition in which the routing stops for this reason...
Anyway I'll post you the correct configuration as soon as possible.. Thanks a lot...
Joseph

I think maybe it's still a problem but not sure how to solve it. The fact that routing stops outside of the definition of the polar is actually a feature, but often interpreted as a bug.

Maybe you can suggest a better way to handle polars, but simply extrapolating them like expedition or other programs is misleading, so if we decide to do it, it needs to be clear. Maybe an option for it?

[stelian]

Originally Posted by joseph79

Dear Alexandra,
which is the correct path of the current file WeatherRoutingConfiguration.xml that I' Using in order to post the correct one?
Regards.
Joseph

On Windows: C:\ProgramData\opencpn\plugins\weather_routing\

On Linux: $HOME/.opencpn/plugins/weather_routing/

[joseph79]

Originally Posted by stelian

On Windows: C:\ProgramData\opencpn\plugins\weather_routing\

On Linux: $HOME/.opencpn/plugins/weather_routing/

Thanks a lot Alexandra,
I hope that now I'm posting the correct files..
Kind regards
Joseph

[stelian]

Originally Posted by joseph79

Thanks a lot Alexandra,
I hope that now I'm posting the correct files..
Kind regards
Joseph

Didier and Sean were right, your polar doesn't allow winds below 6kt, and this is why it fails.

I've modified your boat to use my polars instead: sail if wind 6 kts, motoring if below 6 kts. Add both of the polars to your boat, and your routing will succeed (and if you look closer, you'll notice the small squares on the route, which mean "sail changes", in this case going from sail to motor and backwards.

(you should have one polar per sail configuration -- motoring is just a special sail configuration where you don't have any sails --, in order to tell WR how your boat behaves on a given wind data)

[stelian]

Originally Posted by boat_alexandra

If you want this and it is your intention, then just add a 0.0 boat speed for 0 wind speed column to the polar for all wind speed directions. Don't use "0" because this is interpreted as "not possible". I know this is also very confusing. It would allow you even to avoid sailing against the wind at a higher wind speed, or even dead down wind in light wind which might be very useful, so it's a feature as well.

Sean, I've tried to modifiy the polar in order to add a 0 column, but it still fails the routing. Am I doing something wrong ?

[joseph79]

Originally Posted by stelian

Didier and Sean were right, your polar doesn't allow winds below 6kt, and this is why it fails.

I've modified your boat to use my polars instead: sail if wind 6 kts, motoring if below 6 kts. Add both of the polars to your boat, and your routing will succeed (and if you look closer, you'll notice the small squares on the route, which mean "sail changes", in this case going from sail to motor and backwards.

(you should have one polar per sail configuration -- motoring is just a special sail configuration where you don't have any sails --, in order to tell WR how your boat behaves on a given wind data)

Dear Stelian, thanks a lot for your promt support... with yout polar the Routing reached the destination, also with my polar with additional velocity values related to 4 Ktns and 2 Ktns.

So, now it's clear, the problem is the fact that my polar doesn't show values for wind lower than 6Ktns..

My question is why the software does not interpolate this values uo to 0..?

Just the last question.. I created a no go zone with draw plugin in order to avoid land on routing.. but when I compute the routing an arror message appears as indicated on the jpg file... Where I fails on the setup?

Thansk to all and sorry for this trivial questions... they are trivial but important for me..

[seandepagnier]

Originally Posted by stelian

Sean, I've tried to modifiy the polar in order to add a 0 column, but it still fails the routing. Am I doing something wrong ?

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.

Originally Posted by joseph79

My question is why the software does not interpolate this values uo to 0..?

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.

Just the last question.. I created a no go zone with draw plugin in order to avoid land on routing.. but when I compute the routing an arror message appears as indicated on the jpg file... Where I fails on the setup?

Sorry about this. I didn't test the draw plugin much. You would need to provide your ocpn draw plugin gpx file for the boundary so we can reproduce it.

What version of the draw plugin did you use.

Thansk to all and sorry for this trivial questions... they are trivial but important for me..

Actually it's great you are asking. We can improve the software.

[stelian]

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.

I think something is wrong.

I've added 0.0 at 0 degrees and 0.0 at 150 degrees (see screenshot), then hit "Save", then hit "Save boat".

Route still fails.

And even worse, if I now open the polar dialog again, the entire "0" column is gone (see second screenshot).

(in case it matters, this is with latest WR git and latest OpenCPN git master)

[stelian]

Originally Posted by joseph79

Just the last question.. I created a no go zone with draw plugin in order to avoid land on routing.. but when I compute the routing an arror message appears as indicated on the jpg file... Where I fails on the setup?

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).

[rgleason]

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