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[cmonkey]

Inkscape does svg.

[TommyGober]

Dave I'm excited to see his Activity released.

Will it be possible to change the color pallet from black-on-red to black-on-white? Maybe have user-defined colors?

[Tortuga]

Alternatively, if somebody has a free drawing program for Windows that outputs SVG, I'll take a crack at installing it on my workstation.  (My XO is my only linux box, so a linux-targeted tool is of no use.)

This site: Math Games, Vector vs. Raster by Ed Pegg Jr., August 1, 2005

http://www.maa.org/editorial/mathgames/mathgames_08_01_05.html

has a comparison of a number of free programs, lists their features, OS they work on, and costs,. Here are two that might be of interest:

GEONExT -- Intuitive, powerful, multilingual. Java/HTML save.
Z.u.L. (or Compass and Ruler) -- Excellent. Java/HTML save.

[davewa]

Dave I'm excited to see his Activity released.

Will it be possible to change the color pallet from black-on-red to black-on-white? Maybe have user-defined colors?

There are two option buttons:  "night vision" and "invert display".  "night vision" substitutes red for white to preserve your sensitivity to dim light and "invert display" determines whether the stars and constellation figures plot as black or whether the background plots as black.  So your pallet choices are white-on-black (the default), red-on-black, black-on-white or black-on-red.
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Here's an example of the "night vision" display, taken from the XP development environment.  In Sugar, it looks similar.

[davewa]

Last night's hacking has added the capability to specify a date/time and time zone offset.  So I can now plot the chart for anywhere on the globe and any time within the Gregorian epoch.  (Accuracy suffers beyond +/- 50 years, though.)

I've still got more code to write to get the planetary plots going and two more features to add -- one easy: select how dim the stars can be and still be plotted and one hard: display the star's name when you mouse-over it.  Then there's a little clean-up I need to do: the program presently doesn't handle invalid input in the four text entry fields that specify your locale and time.

Anyway, it's probably going to need another week or two of work to finish it and package the activity for distribution.

[wolf9545]

From looking at your pictures it looks like you have to give it your lat and long.  Is there anyway you can have a drop down list of major cities?  That way if we don't know our lat / long we can just choose a city near us.

[davewa]

From looking at your pictures it looks like you have to give it your lat and long.  Is there anyway you can have a drop down list of major cities?  That way if we don't know our lat / long we can just choose a city near us.

That is possible, but it becomes an internationalization headache and would bloat the program with a large table of coordinates (or require a database file as part of the package).

I think it's easier to simply search the internet for the coordinates -- there are sites which can give you lat/lon for just about any town in the US (and probably other sites for other countries).  Or you can use Google:Earth or a GPS.

For the purpose of this program, latitude and longitude to the degree is acceptable -- one degree of longitude (at the equator) is around 70 statute miles.  You can read that off a roadmap or an altas.  But filling a table of cities and towns to cover the world's landmasses to the resolution of a point every square degree would be an enormous list.

(And I discovered that the XO's implementation of a combo-box control is brain damaged if you have to scroll the list of selections!)

[xojimox]

davewa:

Here's a mars SVG that I made in Illustrator. Let me know if it works.

[davewa]

davewa:

Here's a mars SVG that I made in Illustrator. Let me know if it works.

Thanks.  I can use that for debugging purposes.

[xojimox]

mars.svg (1.26 KB - downloaded 10 times.)

What I want to know is who the other 9 people are who downloaded the SVG.

[TommyGober]

Call us curious lurkers.

[AuntiMame]

What I want to know is who the other 9 people are who downloaded the SVG.

"Me," Aunti sheepishly raises her hand. As curious as a cat, but not dead yet. 

[davewa]

Got the star brightness selection code going last night.  I had to trim down the toolbars, though: Sugar draws gtk widgets larger than normal.  Effectively, the window size when running on my XP box has to be reduced to 725 pixels wide by about 675 pixels high to match what the available screen real-estate is under Sugar on the XO.

I'm still hacking the planetary code -- what's in the program as of last night is not plotting the planets in the proper places (and I can't detect a systematic error).

Anyway, we'll have to see what the weekend's coding brings...

[goney3]

Just from looking at the current development .... is there a way you can iconify the user interface? ... I am sure most 6 year olds would see "Invert Display" and not know what that means. Words like "Zone Offset" and "Night Vision" might get confusing for an amateur novice.

[moocapiean]

mars.svg (1.26 KB - downloaded 10 times.)

What I want to know is who the other 9 people are who downloaded the SVG.

\me raises hand.  I got curious.