Celestial Navigation Plugin Redux

[seaward 42]

I'll do faster with pen and paper

[NAV]

Originally Posted by nohal

Can you please temporarily remove the file C:\ProgramData\opencpn\plugins\celestial_navigatio n\Sights.xml and try again. If it "helps", we will need the file, so please don't delete it completely...

Yes, it helps .

It's the file containing the data I used to test the first version of celestial. In the past it didn't give any problems. File should still be the same, but the only differences are the updates of Windows (from W7 to W10) and OpenCPN (from 4.0 to 4.2) and possibly Celestial. See attachment.

[nohal]

NAV...
Interesting, seems to be specific to Windows. But now I can reproduce, so should be able to fix it.

Pavel

[seandepagnier]

I have updated the plugin to support lunars. Also improved the UI a bit.

[nohal]

Sean...
It seems that the "hang" on Windows with NAV's Sights.xml posted above is caused by enormous values for heading entering resolve_heading and resolve_heading_positive
I have no idea about the underlying logic, so suppose you might be faster in finding out why...

Pavel

[seandepagnier]

A problem somehow exists with 4.2 on windows when you add a second sight. There was no problem with 4.0. I didn't get a chance to debug.

[rgleason]

Built a clean version of celestial_navigation_pi-2.0-ov4.2-win32 from Sean's repos, this has UI changes and does not have Pavel's pull request for language files.
-It is on file thingie.

This new version is using a revised sight.xml (version 2.0) which has a few changes in date format and adding AM/PM to time, etc. if you look carefully at both versions of the sights.xml files. NAV I suggest reentering your sights.xml data. I tried changing one record unsuccessfully.

I have been testing it as best I can. There are a couple of problems so far:

1. When I adjust the transparency slider, the menu freezes and O eventually bombs.
-So for the time being DO NOT Adjust the transparency.


I have moved the earlier version that seemed to work, into Earlier Plugins folder.


--
Haven't checked yet to see if these NAV changes were made.
http://www.cruisersforum.com/forums/...ml#post1456516

[rgleason]

Yes, Sean there is a problem with entering the second sight. Program freezes. I suppose the 14 warnings might help, see attached.

Sight.h

#include <list>

#ifdef __MSVC__
#include <float.h>
#include <iostream>
#include <limits>
#define NAN std::numeric_limits<double>::quiet_NaN () <------
#define INFINITY std::numeric_limits<double>::infinity () <------

#define isnan _isnan
#define isinf(x) (!_finite(x) && !_isnan(x))

#define trunc(d) ( ((d)>0) ? floor(d) : ceil(d) )
#endif

It has trouble with lines 35 and 36

Eample of the 14 warnings.

c:\users\..o-plugin\s-celestial_navigation_pi\src\
Sight.h(35): warning C4005: 'NAN' : macro redefinition
[C:\Users\..\o-plugin\s-celestial_navigation_pi\build\celestial_navigation _pi.vcxproj]

c:\users\frederick\documents\github\o-plugin\s-celestial_navigation_pi\src\
Sight.h(36): warning C4005: 'INFINITY' : macro redefinition
[C:\Users..\o-plugin\s-celestial_navigation_pi\build\celestial_navigation _pi.vcxproj]

[NAV]

Besides the hanging that occurs when trying to change transparency, I also noticed that the main window of celestial is transparent and almost illegible.

[NAV]

The strings 'Distance' and 'Bearing' of the language file are overwritten by other translations from another language file.

In Dutch the nautical expression for distance travelled/to travel ('Verheid') is different from the general expression ('Afstand'). Same applies to bearing, for which the Dutch nautical expression is 'Peiling', although sometimes the general expression 'Richting' should be preferred. All depending on context. And for Celestial there are some more words I like not to be overwritten.


Is it possible to implement the method JonGough used for Watchdog and Draw?

[rgleason]

See "plugin usage of own language strings" here http://opencpn.org/ocpn/internationalization_plugins
Jon also modified demo_pi to show how this can be done.

[Alan Hoeneisen]

I recently downloaded the Celestial Navigation plugin for OpenCpn. I have OpenCpn 4.4.0 running under Windows 10. The plugin behaves as follows: Enter the first sight with no problem. The COP appears on screen. Enter a second sight, click OK and the program freezes. Have to shut OpenCpn down.
In general find the plugin very interesting. In order to make the application even more user friendly perhaps consider something along these lines: On the Sight Reduction form next to “Celestial Body” add a second button. Lets call it GetCB (get my celestial body). GetCB is only enabled if there is an Altitude Measurement entry. Also add a max intercept box (MaxI). What hapend if you click on GetCB. The software checks to see what celestial body return an intercept < MaxI. (it has the required info to do so). If MaxI is reasonably small the odds are that only the observed CB will be selected. If this is the case, it is selected in the Celestial Body box. (This will be the most common situation).
In the case of more than one CB meeting the above criteria display them with their Z. The user then clicks on the CB with the correct Z, it appears in the CB box. Z's of CB that meet the above criteria will be far apart making it easy to tell which is the correct one.

[seandepagnier]

I believe the bug is fixed in the latest version. Can you try 4.4?

As for finding the body. Currently if you choose the body it can tell you where it is in the sky. If you want it to actually list the closest body, you would have to enter both the incline and azimuth.

What is the purpose of this? Is it to shoot stars without knowing which one it is?

[Alan Hoeneisen]

I downloaded the plugin from the OpenCpn plugin page. The version is 2.0 (perhaps the link should be updated). Where do I find version 4.4? CB=celestial body
Regarding Celestial navigation must admit I have not used my sextant in years. Navigated with it from Mid 70's to early 90's. The other day took a sight to check your plugin (my mirrors are in bad shape).
Regarding the “Find” button. A user takes a sight. He is not sure what star or planet it is (Not that familiar with CB's or perhaps it was a partially cloudy day). How does he figure it out? Try one CB click “Find” to see if that is the one. If not, try an other etc etc till the right one shows up. Why not have the software go threw that search. In the old days I had the selected stars tables and a star finder to identify CB's, so it was easy. I think that the assistance you should give the user is a hint of what CB was used. A star finder button (GetCB) would go the other way than the current “Find” button. With the data already entered, (date time, lat, lng, Hs and yes to be correct the user would have to also enter the Z) you can figure out what CB was used. WHAT IS THE PURPOSE OF THIS? Just as you have done all the calculations in the background (no more Hs corrections, no more looking up Almanac data , interpolating etc etc) it makes it a little more user friendly.
Regarding Z I ask myself if the additional input can be avoided. The simpler the better. At any given time you will have of the order of 30 navigation CB's above the horizon. Pick one at random. Take a sight. How many CB's will have a intercept < 30' . I would say the odds are very high that only one meets the criteria.
In the old days use to write navigation programs for programmable calculators. When it came to the almanac it was limited to the sun an Aries. At times still give a 40 min crash course on Celestial Navigation not using any fancy terms. The idea is to keep it SIMPLE so people get the basic concept without getting lost in the woods. You can go to bebinka.net. In Software view help of “Sight Reduction”. In the 70's wanted a sextant with one button that would register a sight data (time,Hs,Z). The idea was to point at a CB, click. Point at a second CB click and it would return a fix. The software was no problem. On the other hand at the time the sensors required were still not invented. Eventually they were all invented including a very accurate digital clock that came with a GPS. So to keep things simple opted for the GPS. Have a nice day.

[rgleason]

Alan, try the main website where there is User Documentation, Downloads, Tracker and the Forum links.

Download OpenCPN | Official OpenCPN Homepage

Sean will have some thoughts about your good suggestions for ease of entry, I believe.