Notices

By the way, I forgot to mention that you should probably move all further announcements, etc. of the Mephemeris program (and this existing thread if possible?) to the Apps forum so that more people will get to take a look at this fine program. (I am fairly new to ITT forums myself so I am not quite sure how that all works, but the Apps forums seems like the logical place).

See ya around...

darethehair, you really out did yourself. Incredible update. Really keep developing. You have a really amazing app here. sun rise/set graph is nice addition. TIA

I'm trying to install on N800 diablo, but can't find the required python2.5-gpsbt in maemo extras. Do I have to install from the bora maemo-extras?

go into red pill mode in application manager(look in threads for how to get into red pill). that should bring it up. then load the apps darethehair says to install on his website. If you are missing any repositories go to www.gronmayer.com/it and download maemo extras if you don't have it. really great app.

I want to thank you guys for the positive feedback given for Mephemeris! In our 'free and open source' environment, that is about the only thing to keep us going, right?

Despite the good things that are being said, I still have this fear that, one day, I will receive a stern email saying:

"Mr. Enns: You are attempting to code greatly beyond your skill limits, without proper training and approval. Please refrain doing from doing so, and immediately remove your code from the internet. We recommend that you restrict your efforts to something you are qualified to code."

Until that email arrives, however, I continue to work on the next version, which is proving to be equally annoying and challenging...

P.S. Also, it looks like your suggestion to move this thread to 'Apps' has succeeded!

Hello again, darethehair! Well, don't worry about any "stern" messages. All programming contributions are welcome in a "free and open-source" society. Besides, whatever "limitations" you may have, you seem to be working around them quite succesfully. Mepemeris is great fun to use!

As an aside, I used to do lots of programming on old mini-computer systems many years ago (even wrote a successfull chess-playing program in Pascal and translated it to the PC). I pretty much stopped programming with the advent of object-oriented languages. Seeing your success, perhaps I should take a look at Python.

At any rate just keep on chugging along. It doesn't matter how "tight" your code is, you have created a very useful and fun scientific program. I will certainly be looking forward to any further upgrades to Mephemeris!

Have fun coding and see ya around...

I like the program but have two criticisms. First, you need to use threads. When I ask for some complex update, it appears to crash but is just lost. For example, the above problem with GPS. It will turn it on and take minutes to get a fix, and not return to the caller. You should change that so maybe it turns yellow until it gets a GPS fix update. Same with the star screen with too many stars. If you don't want to use threads, at least set an exception handler and a way to abort and return to the base screen.

I am also sure you're proud of the opening screen, but it uses an unnecessary slot (and I don't know the hildon magic to show one icon with a little number 3). After starting, overwrite the image with the main screen.

Also the fonts are tiny - some aren't quite readable like the star names (and blurry under a magnifier since the letter M needs to be more than a few pixels wide). Zooming makes the stars farther apart but doesn't make the fonts bigger.

The toggle section, where you can queue the on/off toggles should just say on if it is on, and tapping will turn it off. A lot of screen real-estate is being used, so I would try this or other things to economize.

I don't mean to discourage you since I was working on my own version but yours is far better already, but could be improved.

One other feature - there is/was a program for the Palm called Planetarium by Aho. Similar to yours but it also had a compass mode that would plot a compass with a line in the direction of the star or planet, and in an adjacent half-circle, how far above or below the horizon, sort of like a primitive sextant. But it was useful for locating things.

http://www.aho.ch/pilotplanets/

Hello tz1!

You are the first one to offer some constructive criticism of the actual Mephemeris program, and I thank you for that.

Actually, I am getting very close to releasing another major update to the program, and it includes some of the suggestions you have already made (e.g. font size). However, in case it was not clear in the docs, my skills are quite pathetic for the challenges of writing this program, and I am not at all certain that I will be able to implement some of the fancier improvements that you have suggested i.e. threads and combined banner/start window -- but I will at least try to read up on them

I am pleased that you have started your own app! Are you using the PyEphem libraries, or something else to do the calculations? If your OOP skills are better than might (and they almost certainly are) I am sure that you will come up with something superior to my own app

If you can stand a bit more constructive criticism ...

First, put up separate tarballs (.tar.gz or .tgz) with the development tree. It is easier to edit in a box than in /usr/bin.

Second, come up with a non-gps-bt version since Python-gpsbt is unique to the tablet, i.e. isolate the interface to a gpsinterface.py which would be what you have now for the tablet, or a dummy if I wanted to run under generic linux or something else with pygtk (mac, win), or use gpsd if I wanted it under my laptop plus gpsd (I could probably write one, I already have a dashboard for my motorcycle in python which used gpsd).

The one I did uses star catalogs from the internet and equations from Meeus' Astronomical Algorithms http://www.willbell.com/MATH/mc1.htm which has the basic math. Written in C with a GPSD frontend that called the routines to get elev/azim and plotted to a .png file (orignally for the Sharp Zaurus). I didn't have zooming, but just got the planets, stars, moon and sun in the right place so I could compare to the night sky.

Good programs take time. Mine are usually ugly to start but work, since you don't usually know beforehand what really works and doesn't and where the slow spots are. So I would encourage you to refine it. This is the best way to learn the art of programming. When no one can patch your code to improve it, you've mastered it.

I've been working on GPS logging (saving KML off with vehicle status, moving maps, the dashboard) for over three years - and although it works, I need some tweaks to minigpsd. I also was able to write a very fast mapping program (zmapper - see www.zdez.org) for the zaurus, but my data sources are from the US census, and they changed formats. I need to make it tablet friendly, not just something back in the system so I'm also doing a python front end. You will find some pleas from me and the results about how to do taskbar and statusbar apps in python.

The largest impediment is that I get paid to do embedded work (my current one involves an ARM device running linux that is binary and library compatible with the tablets!), but there aren't a large number of master programmers, and extra steps take time, space, and power. There are a lot who can just pump out code (which usually takes twice as long to fix). The difference is taking the time to master the art, the same way great musicians practice for hours. If you enjoy it they go by faster and it isn't like work.

And you have a large portion of the opensource community to mentor you, something I didn't have when I was learning.

Hello All astronomy folks!

I have put up the latest/greatest version of Mephemeris, after spending lots of time (and hair pulling) over the last month or so:

http://darethehair.googlepages.com/software.html

The changes that I noted in the README file:

2008/10/08 = version 0.97
- add plot text font size setting option
- add Google static map download to Web section (two places)(highly tentative!)
- add viewpoint alter option to polar map mode (lots of work!)
- add ecliptic reference line option to plots
- add galactic reference line option to plots
- add moon plot window for 'mars/jupiter/saturn/uranus ' objects
- add controls visibility/brevity options to sky plot window
- add artificial satellites display option to sky plot window
- add partial NGC catalog plot option to sky plot window
- add Milky Way semi-transparent overlay option to sky plot window
- add 'sun compass' option (basis suggestion from a user)
- add A and B rings to saturn moon and sky plot windows
- add non-Maemo 'gpsd'-based GPS option to supplement existing Maemo 'gpsbt' option
- add image URL source information to most web window download options
- add multiple static user-selectable image download options to web window
- add image scaler for downloaded images
- add solar system plot window for 'sun' object
- add moon phase plot window for 'moon' object
- add FAQ section to the README document
- change layout of 'web' window (again) to support new options
- change to larger sizes on some web image downloads if web window is in full screen mode
- change sky map 'select/enter' option to toggle equatorial/polar instead of equirectangular/polar
- change all unnecessary window destroys to table/vbox destroys instead (less flicker)
- combine splash and main windows into one (very ugly, but it seems to work)
- remove 'rise/set' plot option from 'moon' object window (to make room for 'phase' window)

If you want an accurate depiction of the angle of Saturn's rings, you will also have to upgrade your version of PyEphem to at least 3.7.3.3 (also uploaded and mentioned on the page above).

Thanks to all that provided positive feedback over the months. I specifically took efforts to include suggestions by Dan (more images), and TZ1 (gpsd, compass, etc.). Some of the suggestions were clearly beyond my ability (i.e. threading).

Part of the README file now includes a large 'FAQ' section, which I hope will shed even more light on the decisions/challenges that I faced, and will hopefully answer even questions you haven't thought to ask yet

I am surprised to find that Mephemeris is now almost 10000 lines of code! I don't think I would have started this if I had known what was required for the functionality that I wanted.

I do not expect to add a lot more from now on, but we will see! I would now like to 'take a break' from this and hear back from you folks on how you actually use it i.e. what features do you like, do you also run it on your desktop, etc.. Depending on what you guys say, I might 'advertise' this a bit more *outside* of the tablet world (since it is cross-platform Python after all!).

I fear that in doing the finally packaging for this release, that I may have done something silly and 'broken' one of the old features -- but I suppose you will let me know if I have, right?

P.S. You will probably find it *slower* when drawing the polar displays and grids -- this is because the 'polar' view is no longer a single static plotting -- but allows 'navigation' as on the equirectangular view -- which means that a *lot* more calcuations are required. You have been warned!