Climatology

[Taarnskov]

Climatology data is very interesting for planning purposes and the way the data is presented graphical is very useful.

I believe there is a potential problem when it comes to the use in a mathematical model.

If the accumulated data tells you that, there is a 50% chance for easterly wind and a 50% chance westerly wind. What will you then use in the route planner, when going from east to west?

This is naturally a hypothetical and very simple example but not that far from reality.

Lars

[rgleason]

Yes Lars, this is a good question. 50% of the time it will be against you and 50% with you. I don't know what Sean's algorithm is (I could perhaps find it in the code) but what I suggested was taking each directional vector x % frequency and summing the vectors. This would result in an overall weighted vector which would represent the weighted average. Then sail by that.

Yes it would take longer than if you were sailing with it for 50% of the time and less time than if you were sailing against it for 50% of the time, but that is what we want.

[rgleason]

Dear Ivica,

This looks like a great resource which could be implemented when cruisers have internet for more detailed planning.

...to get ascii, but can get it directly loaded via lib into memory.
In that sense if you get model lon , lat variables then define your domain of interest say btw lon1,lat1 and lon2,lat2 you can get indexes that you need to get (subset) and than just grab them, not whole model result. I can write you example in python how to load just subset of data that could be implemented within plugin.

Good examples:

In my case of the Adriatic Sea I can slice it easily for example:
http://home.irb.hr:40088/thredds/dod...130521.nc.html
it is WRF file holding all info from the model, but if I need only say U10 wind and for 1 time step and predefine region I can just submit that into query
http://home.irb.hr:40088/thredds/dod...[90:1:104]

I think Sean will like this possibility/new feature! Thank you!
Perhaps you could attach a text file with your example code when you get a chance?

Can you explain just a little how you use this personally? It might help us conceptualizing...

Thank you for joining and adding your skiills!

[seandepagnier]

Originally Posted by rgleason

Fourth Line:

Are these errors are warnings? I know what I'm doing and dont really appreciate visual studio trying to correct things that work.

Originally Posted by Taarnskov

I believe there is a potential problem when it comes to the use in a mathematical model.

If the accumulated data tells you that, there is a 50% chance for easterly wind and a 50% chance westerly wind. What will you then use in the route planner, when going from east to west?

Yes this is exactly the tricky thing. So there are best/worst case possibilities. Currently in this case I use the average wind speed whichever way it occurs the most. It may make sense to pick one wind half the time the other wind half the time. Also maybe it is good to use grib data to extrapolate to which wind is most likely this time. Lots of possibilities discussed before. For mostly prevailing areas this is not really an issue.. so they are great for use in routes. This problem has been discussed earlier in this thread.

Originally Posted by ivica

Hi members,
I really like your idea about overlaying additional useful data on the opencpn!
As I am physical oceanographer running atmo/ocean models in real time *WRF high resolution, ROMS nested etc* and serving them via opendap TDS server it could be possible to reduce size of the data needed for download.
As you can access TDS servers and just grab
1) variables that you need (i.e. only wind, current, mslp)
2) get data only for certain region (subset)
3) get data only for certain dates (subset)
All data are already netCDF so that should not be the problem as I can see you have developed netcdf part of the lib.
If I can be of any assistance I would be glad to help, I am running opendap TDS server and can give you info if need.
For test I could run it for my domain that I have under control and easily we can apply it worldwide.

Only wind and current data are large enough datasets that you might consider getting something less than the whole world.

Well the raw input files are compressed netCDF. So this somewhat complicates things for partial gets, but maybe you can do it?

Once the data is compiled down which only one person needs to do, I reduced the data it so currents is under a meg, and wind is 3-4 which should be small enough for users to just get the whole world. I think I can reduce wind down to 1 or 2 in the future and also improve it. Once I add indicies the data size will go up a lot though.

So maybe instead we need to look at subdividing the compiled data, and adding support to the plugin to automatically download whatever bits it needs.

I added precipitation data today. I have air temp and humidity, but many holes in the data.

[ivica]

just reply on my part of the post...
depending on resolution you want, i.e. I have 2km resolution so it is not the same getting whole domain every 3hours or not. Moreover if you are on the boat with mobile connection.
My model data, and majority of other models are not compressed netCDF, i.e. version 4, but could be say bz2 which is again bunzip2ed for you at the server side, not locally. So at the end you do not notice this, it's done behind. Possibly you can save "scaled netcdf", with short format variables and use offset, scaling factor, there are many possibilities to reduce size. Compare double precision with signed(or even unsigned) integer (say pressure, temp, wind are ideal for that).
Cheers,
Ivica

[rgleason]

Sean, you're back.

I know you know what you are doing(!!!!), you wrote the OpenGL api . The XXXX thing BREAKS in MSVC, as outlined above. It is an initialization problem for "r", "g", "b" I believe.

Are these errors are warnings? I know what I'm doing and dont really appreciate visual studio trying to correct things that work.

I don't know what I am doing all the time, so I don't know if it is visual studio interrupting. I will try to get a photo of the message, which is followed by a break.

Run-Time Check Failure #3 - The variable 'g' is being used without being initialized.

Nevertheless, there are problems with the windows version. As detailed above, and in the release version.

From Post 63

The checkboxes for Wind and Currents does not cause a break unless Isobar is checked in config.
The checkboxes for Pressure, Sea Temp and Cloud cover cause a break whether or not Iso is checked.

The cyclones do not work at all. They do not fail or break on checking the box.

Tried the Release version, similar problems. Hangups not as immediate.

[Taarnskov]

I planned a route from Gran Canaries to St. Lucia as you can see on the screen dump. The route was based on climatology data. I believe this a rather unusual route. What went wrong.

[rgleason]

Series of screenshots attached. Last one shows the MSVC message.
(Maybe this is something left over from the Error Reporting System that Pavel asked me to comment out in the Cmake file? See Post #61 ).

Nevertheless, here is the Call Stack after a break with the message.

climatology_pi.dll!0f0cae51()     
     [Frames below may be incorrect and/or missing, no symbols loaded for climatology_pi.dll]    
     climatology_pi.dll!0f0ccdbd()     
     climatology_pi.dll!0f0d00ce()     
     climatology_pi.dll!0f0e260c()     
>    opencpn.exe!PlugInManager::RenderAllGLCanvasOverlayPlugIns(wxGLContext * pcontext, const ViewPort & vp)  Line 733 + 0x20 bytes    C++
     opencpn.exe!glChartCanvas::DrawGLOverLayObjects()  Line 675    C++
     opencpn.exe!glChartCanvas::render()  Line 1806    C++
     opencpn.exe!glChartCanvas::OnPaint(wxPaintEvent & event)  Line 630    C++
     wxbase28ud_vc_custom.dll!wxAppConsole::HandleEvent(wxEvtHandler * handler, void (wxEvent &)* func, wxEvent & event)  Line 323    C++
     wxbase28ud_vc_custom.dll!wxEvtHandler::ProcessEventIfMatches(const wxEventTableEntryBase & entry, wxEvtHandler * handler, wxEvent & event)  Line 1241    C++
     wxbase28ud_vc_custom.dll!wxEventHashTable::HandleEvent(wxEvent & event, wxEvtHandler * self)  Line 907 + 0x1c bytes    C++
     wxbase28ud_vc_custom.dll!wxEvtHandler::ProcessEvent(wxEvent & event)  Line 1301 + 0x1c bytes    C++
     wxmsw28ud_core_vc_custom.dll!wxWindow::HandlePaint()  Line 4617 + 0x1c bytes    C++
     wxmsw28ud_core_vc_custom.dll!wxWindow::MSWWindowProc(unsigned int message, unsigned int wParam, long lParam)  Line 2747 + 0xb bytes    C++
     wxmsw28ud_core_vc_custom.dll!wxWndProc(HWND__ * hWnd, unsigned int message, unsigned int wParam, long lParam)  Line 2618 + 0x1c bytes    C++
     user32.dll!769362fa()     
     user32.dll!76936d3a()     
     user32.dll!76936ce9()     
     user32.dll!76940d27()     
     user32.dll!76940d4d()     
     opengl32.dll!19c560fb()     
     user32.dll!769362fa()     
     user32.dll!76936d3a()     
     user32.dll!76936ce9()     
     user32.dll!76936de8()     
     user32.dll!76936e44()     
     ntdll.dll!77cc010a()     
     user32.dll!7694131c()     
     user32.dll!76941332()     
     user32.dll!7693788a()     
     wxmsw28ud_core_vc_custom.dll!wxEventLoop::ProcessMessage(tagMSG * msg)  Line 80    C++
     wxmsw28ud_core_vc_custom.dll!wxEventLoop::Dispatch()  Line 294    C++
     wxmsw28ud_core_vc_custom.dll!wxEventLoopManual::Run()  Line 115 + 0xd bytes    C++
     wxmsw28ud_core_vc_custom.dll!wxAppBase::MainLoop()  Line 312 + 0x15 bytes    C++
     wxmsw28ud_core_vc_custom.dll!wxAppBase::OnRun()  Line 368    C++
     wxbase28ud_vc_custom.dll!wxEntryReal(int & argc, wchar_t * * argv)  Line 448 + 0x1b bytes    C++
     wxbase28ud_vc_custom.dll!wxEntry(int & argc, wchar_t * * argv)  Line 209 + 0xd bytes    C++
     wxmsw28ud_core_vc_custom.dll!wxEntry(HINSTANCE__ * hInstance, HINSTANCE__ * __formal, HINSTANCE__ * __formal, int nCmdShow)  Line 386 + 0xe bytes    C++
     opencpn.exe!WinMain(HINSTANCE__ * hInstance, HINSTANCE__ * hPrevInstance, char * lpCmdLine, int nCmdShow)  Line 747 + 0x1c bytes    C++
     opencpn.exe!__tmainCRTStartup()  Line 547 + 0x2c bytes    C
     opencpn.exe!WinMainCRTStartup()  Line 371    C
     kernel32.dll!767f33aa()     
     ntdll.dll!77ce9ef2()     
     ntdll.dll!77ce9ec5()

Sean, I do hope this has been helpful. It would be nice to have it running in Windows OK so people can use and test. Let me know if you want more runs or whatever. That is exciting about reducing the size of the data. What did you do? Have more detail at coasts and less in oceans where it is not as variable?

I recently found some formulas that might help wiht calc of fog, that I think I'll email. I wish we could find some historical charts for monthly frequency of fog worldwide.

[rgleason]

When in Climatology Release version, not debug. Config > Pressure Isobar checked.
Then check Pressure checkbox on main menu. Isobar progress bar comes up, runs, high cpu, and keeps running, never completes. Cannot close the plugin or Opencpn. Only way to stop this is to go into task manager and "End Program".

The same thing occurs for Wind, Current, Pressure, Sea temp, Cloud etc.
The problem may have to do with initialization of Units and Spacing, because I notice that when I have set spacing high, Isobar progress bar may not run, and also it seems happier when I have set the units for all Data types. Initially there appears to be no unit set,or at least none appears in the window. Sometimes spacing is set to 1 initially.

[rgleason]

planned a route from Gran Canaries to St. Lucia as you can see on the screen dump. The route was based on climatology data. I believe this a rather unusual route. What went wrong.

Perhaps the plugin has discovered a faster route? but the total distance is significantly more than a direct line.

[cagney]

Originally Posted by Taarnskov

I planned a route from Gran Canaries to St. Lucia as you can see on the screen dump. The route was based on climatology data. I believe this a rather unusual route. What went wrong.

It looks like a reasonable cruising route going from St Lucia to the Canaries. Are you sure you did it the right way around ?

Thomas

[Taarnskov]

Yes i did it the rights way around, and i dont think that any of the ARC sailors have ben that far north durring their crossing.


Lars

[rgleason]

Tried Canaries to St Lucia in September, got similar route.
Then cleaned up Wind and Current settings so I could understand the Climatology better. -My conclusion is that a more direct route would have been faster because there is no current to speak of, and the winds look favorable along a straighter route....

I guess I don't understand how the isochrones developed show less mileage developed along the straighter route. Why is weather routing calculating a remarkably slower passage in the path of the direct route?

When I move the cursor to indicate an alternate route, the direct route is not preferred at all, the yellow route want to avoid a direct route for some reason.

Found an Atlantic route was a little different than expected, and a Nassau-Newport June route did not take advantage of Gulf currents. Don't know if this is optimal routing yet.

[rgleason]

In response to this Atlantic routing, a friend wrote:
"Jimmy Cornell has the direct route heading north and closer to Nova Scotia, then looping a great circle route over to Ireland. Pretty close except for the southerly dip at the beginning. I wonder if it will determine the fastest route within set limits (allowable wind speed, sea state, and using the boat's polars)"

[cagney]

I had to test the Atlantic Route between Antigua and Gran Canaria, using climatology



This is in February, one of the months with the strongest trade winds,
The plugin suggests a more or less direct route from Antigua against the trade wind and the northern loop going the other way. Which means heading up into the West wind belt tacking westwards in the middle of the winter.

This is totally back to front.

Is he plugin using winds 180 degrees out? Or is the polars turned upside down?
Whatever....., the result is badly wrong!


Thomas