getSelectedObjectInfo() - Azimuth figures reported incorrectly

[Alexander Wolf]

Note: This report was taken from our forum - https://sourceforge.net/p/stellarium/discussion/278769/thread/93d4078c/

Hi all!

I think I've come across a bug with getSelectedObjectInfo(), specifically the figure it reports for a selected objects azimuth.

For the record I'm using 0.12.4 64bit on Win 7 Home Premium 64 bit. Also tried with the 32bit version of Stellarium but no difference.

There's a couple of examples below, but if you run the script in the console with an object selected, you'll see similar strangeness

This is the script:
TargetData = core.getSelectedObjectInfo();
TargetName = TargetData["localized-name"];
TargetGeoAzi = TargetData["azimuth-geometric"];
TargetGeoAlt = TargetData["altitude-geometric"];
core.debug(TargetName + "\t" + TargetGeoAzi + "\t" + TargetGeoAlt);

Observer Location: London
 Date: 2013-12-11 04:30 UTC

Target: Arcturus
 Azimuth: +95° 54' 54"
 Altitude: +29° 18' 57"

These are the figures shown in the information panel, top left of screen - all good

And when I run the script, the numbers that come out are haywire.

Script Azimuth: 84.08502474297381 (84° 05' 06.09")
 Script Altitude: 29.31577612575129 (29° 18' 56.793")

The altitude is correct, but the azimuth is not.

It only makes sense with the formula:

180° - Actual Azimuth = Reported Azimuth

e.g.
 180° - 95° 54' 54" = 84° 05' 06.09"

This is only true of objects with an actual azimuth of between 0° and 180°. Things get stranger if you go past 180°....

====================================

Observer Location: London
 Date: 2013-12-11 04:30 UTC

Target: Pollux
 Azimuth: +236° 26' 14"
 Altitude: +57° 00' 46"

Script Azimuth: -56.43734108748945 (-56° 26' 14.4276")
 Script Altitude: 57.01283417030654 (57° 00' 46.2018")

Again altitude is correct, but the situation with the azimuth is worse. Now the formula appears to be

Actual Azimuth - 180° = (-)Reported Azimuth

e.g.
 236° 26' 14" - 180° = -56° 26' 14.4276"

You see what happened? It took the actual azimuth, subtracted 180° to get a result, and then made the result negative!

I also noticed this behaviour with getObjectInfo

Any input greatly appreciated!
 Many thanks
 Richard

[Alexander Wolf (alexwolf)]

A fix has been committed as revision 6426 of the trunk branch in Stellarium's Bazaar repository at Launchpad:
http://bazaar.launchpad.net/~stellarium/stellarium/trunk/revision/6426