OpenCPN 4.6.1 - Weather routing and Land Detection not working

[nohal]

Originally Posted by hasse_A

This is in the log-file.
9:17:05 PM: Loading World Chart Q=0 in 0 ms.
9:17:05 PM: Background world map loaded from GSHHS datafiles found in: C:\Users\hasse\Documents\Charts\GSHHG\
9:17:05 PM: Loading World Chart Q=4 in 0 ms.
9:17:05 PM: Warning: Color not found CHGRD

Actually I do get i more detailed map when the GSHHG entry is in the chart listing.

What if I move the GSHHG file to the OpenCPN program directory ?
In that case what should the directory name be to enable OpenCPN to find them ?
Maybe the weather routing needs to have the base map in the program tree ?

/Hans

No, weather routing plugin does not need anything like that, it calls the main program API to detect land - Do not touch the basemap as it is working exactly as it should.
Your problem is either in the setting of the weather routing plugin you use or in your expectations. We would need to see these to decide.

[hasse_A]

Originally Posted by nohal

Your problem is either in the setting of the weather routing plugin you use or in your expectations. We would need to see these to decide.

Ok this is what I get.
As you can see I get Polar: Land: Failed
whatever this means.

If I uncheck "Detect Land" I get a strait line right over Grenada.

/Hans

[hasse_A]

Originally Posted by hasse_A

Ok this is what I get.
As you can see I get Polar: Land: Failed
whatever this means.

Well, this means that one of the points are to close to land.
If I move the start and end points some distance from land all is ok.
None of the points where actually on land so one would not expect there to be a problem.
Maybe this is a good test case because I think it should have made it.

/Hans

[nohal]

Originally Posted by hasse_A

Well, this means that one of the points are to close to land.
If I move the start and end points some distance from land all is ok.
None of the points where actually on land so one would not expect there to be a problem.
Maybe this is a good test case because I think it should have made it.

/Hans

As far as I can tell, this usually means that you can't "escape" from the close proximity of the land with the rest of your settings (step too big, max deviation off course too small)... There already was some discussion about similar subject, but usually regarding reaching the destination.

[.Paul.]

Hans, nohal,

The starting point at the "Boat" position on the chart is shown on this screen shot (WR_start_chart.png):



The same starting point shown with a "No Charts" chart group selected, leaving only the GSHHG background (WR_start_GSHHG.png):



WR_pi cannot start because it sees land in all directions.

Paul

[nohal]

Well, starting a weather routing from a deep bay facing exactly to the opposite direction is not exactly a good idea even if the GSHHG data were spot on, which they sure are not.

[skipperearly]

Originally Posted by nohal

Well, starting a weather routing from a deep bay facing exactly to the opposite direction is not exactly a good idea even if the GSHHG data were spot on, which they sure are not.

may be "not exactly a good idea to start a routing" but is a great way to test the solidity of the programmed algorithm! - or to invite a more meaningful/helpful error description.

[nohal]

Originally Posted by skipperearly

may be "not exactly a good idea to start a routing" but is a great way to test the solidity of the programmed algorithm! - or to invite a more meaningful/helpful error description.

Well, then you also probably should allow the 180 degree deviation off course...
There is not much to "test" by this, the routing algorithm will of course get you out of that hole if you do not prevent it by your settings.

[hasse_A]

Originally Posted by skipperearly

may be "not exactly a good idea to start a routing" but is a great way to test the solidity of the programmed algorithm! - or to invite a more meaningful/helpful error description.

Exactly. I except that you can not start from a deep bay as the basemap is not correct enough even with highest resolution, but it is a unfortunate that you then can not use Boat position as start point. Even worse is that the error description gives you no way of knowing what the problem is.

If you were able to edit positions after that they have been entered this would not be a big deal.

/Hans

[seandepagnier]

Originally Posted by hasse_A

Exactly. I except that you can not start from a deep bay as the basemap is not correct enough even with highest resolution, but it is a unfortunate
that you then can not use Boat position as start point.

It's possible to use boundary with draw plugin instead and you can trace your map to define where you can sail.

Even worse is that the error description gives you no way of knowing what the problem is.

Has been discussed many times. The program does not know what you are trying to do. So it is equally likely that different reasons can cause the routing to fail. Maybe the boat is not able to sail in some of the conditions present, and if it could, it might manage to find a different route, but otherwise, land prevented the route.

If you were able to edit positions after that they have been entered this would not be a big deal.

You can edit positions. Create a new position with same name. Right click chart to make new position.

[rgleason]

SkipperEarly wrote:

may be "not exactly a good idea to start a routing" but is a great way to test the solidity of the programmed algorithm! - or to invite a more meaningful/helpful error description

This is not a reasonable statement at all. In fact it is totally unreasonable.

1. The computer and program is just executing instructions set by the user using data selected by the user.
2. The user has control over the program and should make the necessary adjustments to complete the routing.
3. Expecting the wxrouting algorithm to magically solve the intersection of impossible geometries, long intervals, and inadequate course deviation, difficult polar files, etc is indeed unreasonable.
4. The user must learn how to use weather routing effectively and not expect success every time.
5. Reading the User Manual several times can be useful.


Suggestion: Move your start and finish points out further away from land. Without using very tight intervals and adjusting other settings weather_routing will often be unsuccessful in coastal situations.


Wiki FAQ


Read this post and Sean's post and others below


Messages in Config Windows

Failures

[skipperearly]

@rgleason: strange that you call a users request for more meaningful/helpful error comments as totally unreasonable.

I defend my opinion, that the current user interface of the weather routing is not user oriented and error messages are not helpful for users.
It is cumbersome to define start/end positions - to edit them (as you suggest) is even worse..... no straight forward drag&drop, no change of coordinates, no standard coordinate format.

I do read the manual - and thank you for all your efforts to keep it up2date.

So far I did not manage to get a weather route calculated first time. It always took me several attempts to finally get some results, and the feed back from the error messages were little helpful as not enriched with details.

[seandepagnier]

I am glad to continue the discussion, but so far it is not really clear what changes should be made to improve the plugin.

Saying the plugin is "not user oriented" is a great way to explain you are frustrated, but doesn't really give me any more clues and is no better than the error messages themselves for describing the actual problem.

So exactly how could the plugin improve?

right clicking the start/end points to change them? Dragging them? How?


What error message should it say?

It just isn't clear why routing fails, since it is a combination of all of the configuration settings that leads to this result. It may be required to change two different settings to succeed any two setting of 8 possible. How can the program give a meaningful error message? It won't in-fact know which settings should change and by how much until they are changed and the routing is tried again.

Unless you can give a clear example of where it did not give a useful error message and it could have and what that message would be, I don't know how to improve this. If you give one error message, but many different error messages are just as valid, then the one given is not really the correct one and can lead to even more confusion.

[skipperearly]

[QUOTE=boat_alexandra;2770395]I am glad to continue the discussion, but so far it is not really clear what changes should be made to improve the plugin.

[UNQUOTE]
Please see the tracker - many bugs/feature requests are already documented there


[QUOTE]
Saying the plugin is "not user oriented" is a great way to explain you are frustrated, but doesn't really give me any more clues and is no better than the error messages themselves for describing the actual problem.

So exactly how could the plugin improve?
[UNQUOTE]

Use the WP and routing functions (including formatting of coordinates, dates and time ) already available in ocpn.

[QUOTE]
right clicking the start/end points to change them? Dragging them? How?
[UNQUOTE]
well exactly as already implemented in ocpn!

[QUOTE]
What error message should it say?
[UNQUOTE]
1st show which grib, polar are used and where the calculation started to fail.

[QUOTE]
It just isn't clear why routing fails, since it is a combination of all of the configuration settings that leads to this result. It may be required to change two different settings to succeed any two setting of 8 possible. How can the program give a meaningful error message? It won't in-fact know which settings should change and by how much until they are changed and the routing is tried again.
[UNQUOTE]

I guess this is where we may have the deepest disagreement. I see the majority of users to just do a simple w_routing and explore special features later. So defaults should be set so that 1st calculate delivers a result not the other way round.

Unless you can give a clear example of where it did not give a useful error message and it could have and what that message would be, I don't know how to improve this. If you give one error message, but many different error messages are just as valid, then the one given is not really the correct one and can lead to even more confusion.

See attached screenshots (dont know of a better way to share this info with you)
Screen 1 shows a unsuccessful attenmpt
Screen 2 is ok but would be nice to have a possibility to make 'intermediate WP's which should be added to the route within a range - so in my example I could add a wp at Otranto with range 100nm and algorithm would not even start to explore options towards Genua

Screen 2 took several minutes to calculate - it would be good when on start of calculation:
- 1st minimise wr-pi dialog
- 2nd zoom so that start and end WP are shown
- 3rd see progress of calculation

Hope this feedback helps to make this wr_pi more popular

[MartinR]

Is this OS related?

For me the weather routing worked perfectly until the last opencpn update. Now the plugin seems not to be able to find the polars. But I am on a Mac and I understand that the author, whom we really have to thank for making this plugin, is doing his coding on a PC.