Different platforms (windows, linux, OSX, etc.) can have slight differences in their floating point number systems. To work around that, numbers are stored as fractions. So Mars' radius(f(533,1000)) is 533/1000 or 0.533 and Jupiter's mass(f(3178,10)) is 3178/10 or 317.8.

The units for radius and mass of planets is in Earth radius and mass. Thus Earth's radius(f(1,1)) and mass(f(1,1)) both equal 1. While Mars' radius is 0.533 times Earth's radius and Jupiter's mass is 317.8 times Earth's.

The units for radius and mass of stars is in Sol radius and mass. Thus Sol also has radius(f(1,1)) and mass(f(1,1)).

As for what numbers to use in the f(x,y): both have to be whole numbers, so mass(f(317.8,1)) would be wrong. Although f(3178,10) could be reduced to f(1589,5) the first is easier for humans to understand.

hmmn. I was never any good at fractions but I think there is just enough info in what you've said there for me to do another pass. thanks heaps!

On a vaguely related note, Charon is already in the game - Hydra and Nix are missing.

Adding satellites to a dwarf planet is all very noble, but there are four other dwarf planets in Sol which have not been added at all yet.

this mission should u choose to accept it is to add the noble dwarf planets that are missing and their companion orbiting moons into pioneer

...No s&&t Brianetta - I pushed for Charon to be added back in build 20. (and was excited when it was) And also- that's pretty much the first thing I wrote in my post. Your tone is always so... Off putting.

But yes mate, sure- As for other celestial bodies , man if I can get that excel calculator to work for me so I can dial in stats from wiki then I'd love to add Huamea, makemake and eris. Wtf not?

I accept! I'd love to add them once I've got a handle on the fraction thingys

You guys are legends!

Have a biscuit...

http://www.youtube.com/watch?v=AwNh36AURGM

that was a great docco!

took me a few days to get through it cause of work but it was great.

think I might fly to Titan tonight and watch Saturn rise.

(have done that from Frontier once before)

I'll admit I am pretty dumb at maths and as a result I still can't see the pattern/work out the equation that is used to determine how you use which fraction when...

Here's a list of radius data from wikipedia, that data divided by earth's radius and the pioneer code lifted directly from sol.lua

wikipedia data data/6378.1km pioneer lua code

radius (jupiter) | 71,492.00km | 11.2089807309 | :radius(f(11,1))

radius(earth) | 6,378.10km | 1.0000000000 | :radius(f(1,1))

radius (mars) | 3,396.20km | 0.5324783243 | :radius(f(533,1000))

radius (proteus) | 210.00km | 0.0329251658 | :radius(f(310,10000))

radius (phobos) | 11.10km | 0.0017403302 | :radius(f(21,10000))

So if a value is bigger than earth it should be x over 1?

If a value is less than earth but over 1000, it should be x over 1000 (I'm guessing to represent the 1st 3 values (10th, 100th, 1000th) after the decimal point)

But why are both proteus and phobos over 10000?

Should phobos be over 100000?

And why is it 21/10000 not 11/100000 ?

Is there an equation at work here to get the Km value (or mass, semi major axis etc) converted to the appropriate (f(f1,f2)) value?

I so confuse 😳

It's a fraction of Earth's radius. If a planet is twice as wide as Earth, it's f(2,1). If it's two thirds as wide as Earth, it's f(2,3).

It's all a ratio of Earth. Earth is about 6,378 km in radius. The easy-peasy way to specify it, therefore, is as a fraction with the desired value first, and Earth's value second. Ceres is about 476 km, so that is like this:

See data/systems/custom/03_elite.lua for how I did the Elite systems. I got the radii of the planets from the alioth.net wiki (here are Lave's details, for example). It shows the radius of Lave as:

Planet Radius: 4116km

...so I coded that in as:

Hope that clears it up, and makes it less daunting.

Ok cool. I got that they were fractions I just couldn't see the pattern. But I do like your easy-peasy method! that should help me a great deal

cheers

@trumpet:

Did you ever come up with a useful spreadsheet?

I'm trying to put together a system right now and it's horrible!

Or to be more precise, I grabbed JonG's FFEStarSys program and wanted to try to recreate the Ache®nar star system... for fun. The process is proving to be... not fun.

For example converting between the values it has and the fixed point ratio-like representation we use is particularly complicated, especially when you don't know which ones actually belong to which value. Lets take the semi-major-axis which isn't what I thought it was I was actually looking for axial-tilt, I think.

EDIT: thinking about it, what might be nice is the ability to simply dump the data for a system straight from the Frontier/FFE data...

I started to. I just couldn't get my head around the fractions aspect. The stuff that Brianetta suggested worked well for radius etc, but I got stitched up on some of the orbital/axial data again. Sorry man. Best laid plans of mice and men...

Achenar would be awesome! That system is bloody huge.

Indeed and it's difficult to understand the current system.

Still I'm slogging my way through it, got the first 6 worlds out of 10 almost in, successfully docked at one of the orbitals <img src="' http://spacesimcentral.com/forum/public/style_emoticons//icon_e_biggrin.gi f"' class='bbc_emoticon' alt=':D' />

Will have to go through and double check everything when I'm done and then it'll need per-world parameters for the atmosphere and things but so far so good.

AaARGH, *headdesk*, having just posted that I realise I've got _all_ of the rotation_period's wrong.

bugger,

onwards!

A lot of issues resolved now, just working on the mass vs radius of the terrestrial (rocky) worlds that you can land on, have star ports etc. Well I say working on it, what I'm doing is bashing my head against the desk.

It wasn't at all obvious how they were related at first and I couldn't take off or land on any for a while. Think I've worked it out now, the rules seem different for stars and gas giants though and I haven't entirely figured them out yet.

However Achernar now has all of the worlds, stations and starports from FFE and it is a pretty cool system already <img src="' http://spacesimcentral.com/forum/public/style_emoticons//icon_e_smile.gi f"' class='bbc_emoticon' alt=':)' />

Submitted a pull request for Achernar re-implementation <img src="' http://spacesimcentral.com/forum/public/style_emoticons//icon_e_smile.gi f"' class='bbc_emoticon' alt=':)' />

Just fyi, we have a new cross-platform number system on the way (the core is written, it just needs to be hooked up to Lua and to the system generator). Once its in, there will be no more f(1,123) - instead you'll just put your number in a string (ie "123.456" instead of 123.456), which will trigger a number class that has been designed to have consistent rounding behaviour on all platforms. So this will get easier <img src="' http://spacesimcentral.com/forum/public/style_emoticons//icon_e_smile.gi f"' class='bbc_emoticon' alt=':)' />

Doh! Why didn't I think of writing that!?! <img src="' http://spacesimcentral.com/forum/public/style_emoticons//icon_e_smile.gi f"' class='bbc_emoticon' alt=':)' />

That'll be good it can get very confusing right now.