Adding the perihelion and aphelion calculations of the planets to AstroCalc's ephemeris

Stellarium / stellarium

Stellarium is a free GPL software which renders realistic skies in real time with OpenGL. It is available for Linux/Unix, Windows and macOS. With Stellarium, you really see what you can see with your eyes, binoculars or a small telescope.

https://stellarium.org

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Adding the perihelion and aphelion calculations of the planets to AstroCalc's ephemeris #874

Closed Ironman65 closed 4 years ago

Ironman65 commented 4 years ago

Is it possible to add to the AstroCalc’s ephemeris the planets Perihelion and Aphelion? like it calculates the conjunctions and oppositions. This would be a nice feature if possible and would be great for calculating the future observations of Mars especially to see if it’s at Perihelion is around its opposition. I do understand as a non programmer that adding a new feature can ether slowdown or even cause the program to crash and burn depending on the code of the program which it is written in, in such cases no feature is worth it specially if it causes it to crash. Again thanks for all that you do.

gzotti commented 4 years ago

This is basically a duplicate of your #850. Again: Stellarium does not compute the orbital elements from which apices could be directly derived and shown in either the main screen or a table, but uses series of cosine terms for the planets' positions. You should be able to make a Curve plot showing just the distance to Mars and run this over 15 years or so to get an idea when Mars is best visible. @alex-w Maybe you could enrich the Curve panel with a larger date range?

alex-w commented 4 years ago

It's not full duplicate of request. For question of graphs - yes, we can extend the graphs, but how much it should be enlarged? 1..10 years since 1 January of current year?

gzotti commented 4 years ago

Well, either 1-30 (~Saturn year?) full years or fully free start and end dates? Clearly, labeling will be a challenge.

alex-w commented 4 years ago

@gzotti please check the English terms in latest changes - I hope this is acceptable and understandable

gzotti commented 4 years ago

A few changes please:

"Graphs since January 1st of the current year"
"Duration (years):" or "Duration: [SPINBOX] years" (and add a spacer between that and ["draw curves"]
The interval spacing is odd (already in the graph for 1 year). Depending on actual duration, could be months, 3-months, 6-months or even full years. The labels must also give years. If partitions are full months, you could omit the day number instead.

alex-w commented 4 years ago

In the our current version of QCustomPlot changing labels type for temporal axis is very problematic. Yes, we can ask authors of newest version of QCustomPlot to allow for us obtain that new version under GPLv2 again, but I don't want refactor all parts for graphs after upgrading QCustomPlot at the moment (if we'll got permission). In any way I've added obvious visual workaround for the borders of the years.

gzotti commented 4 years ago

OK, I did not know these details of QCustomPlot. The year separators are also OK. Now I just rediscovered the 15-year pattern for Mars :-) As great as AstroCalc has evolved, CodeFactor complains already about its complexity. Take care to keep it maintainable!