I dunno. Last I tried it, it was bugged such that it would cause a negative gain of mood, energy, and iMG. It was kinda cool, because it also caused me to un-level, but I'm not meditating again until I get some kind of confirmation that it won't level spam my entire timeline again.
It's complicated. It is not linear with energy (I think it is past a certain point, but not at low energy numbers). Hopefully I'll have some decent numbers in the next couple of days.
I'll do some calculations right now, and see if I can figure it out.
I'll post my finding after.
Edit
Okay so I did quite a few tests with a few people, my conclusion is basically what Humbabella said above. It's definatly based off of time but there's something funky going on considering the average delta between energy gain compared to seconds spent meditating doesn't make sense, even if you take into account the fact that there's probably a base gain involved.
Will crunch more numbers tomorrow, when more people are on to test with. I also need to find a more accurate way of recording the meditation times. x.x
I'm really getting weird numbers out of this. I can find a formula that works most of the time but for certain numbers of seconds it will be off by one like it rounded in the wrong direction.
Okay, I've at least got what happens when you finish meditating rather than interrupt it - you get 10% more (appears to be calculated before rounding). Oh, and note that it rounds up the number of seconds you've meditated.
Unfortunately the amount I've gotten per second of meditating has been pretty weird.
500 energy - 3.33
4000 energy - 9.6
5000 energy - 10.5
6000 energy - 11.7
That the 1000 energy that went from 5k to 6k added more than the previous 1000 energy is very strange. Anyone able to confirm these would be appreciated.
Is getting interrupted only if you do things to stop it (i.e. talking if you don't have the cards, trying to verb stuff in your bags)? I think some people were having problems with it seeming interrupted when they hadn't done those things.
You can tell if it is interrupted by the sound it plays on completion in case there is any confusion. As I said, I'm pretty sure that finishing naturally gives a 10% bonus. At 6000 energy, meditating for 0, 1, 2, 3... seconds gives 12, 23, 35, 47, 59, 70, 82, 94, 105. That's 11.7 rounded to the nearest energy.
At the same energy total, meditating for (23, 33, 40, 41, 43) seconds while naturally finishing gives (309, 438, 528, 541, 566) which just happens to be 11.7 per second plus 10% rounded to the nearest energy. That seems like a little bit too much fo a coincidence.
It works just as well at 5000 energy with 10.5 per second.
I'd like to double check mt 4000 number since I didn't do interrupted meditations up to 10 seconds, I just did 5, 10 and 15. But unfortunately this is something where you can't go back.
My impression is that the cool-down time, for me 1 min 45 sec at level 48, is much longer than it used to be, although I don't recall what the time used to be. Confirmation?
I generally meditate while other activities such as cooking, making eggs, etc are going on. Since it appears that I spend the same amount of time in meditation but more time in cool down, I believe I am now progressing more slowly towards the Master of Internal Emptiness badge. I may be getting just as much energy/mood benefit, but that is of much less concern to me.
Cooldown is based on your maximum energy (though if there is a level component as well I wouldn't be able to tell). Buying my energy up definitely increased my cooldown. Strangely, the amount of time energy per second if you do nothing but stand around and wait for the cooldown seems to have remained about constant. Previously I could meditate two thirds of the time for 2 energy per second. Now I can meditate one fifth of the time for 13 energy per second. I think it's a slight decrease. If you are doing other things, though, it's probably an increase because I used to interrupt my meditation constantly to start new batches of work.
For what it's worth:
Energy tank 13810
Energy received from meditation 300-600
Cooldown 4m36s.
Suppose I'd better get started on those badges... I'll never finish (I think assuming 30 seconds of meditation average, it comes down to 81 hours of grinding for the last badge).
Yeah, I have to say the longer cooldown time affects me also, since I'm still grinding for the badge. Oh well..
I'd assumed that the max energy gain per minute would be relatively constant (to avoid unbalancing), so I guess that, all things being equal, I'd rather be able to get a large chunk of energy quickly.
Unfortunately the per second values go to at least 2 decimal places (6700 energy definitely generates 12.36 per second, not 12.35 or 12.37 - but I don't think there is a number of seconds I could do to test if it is 12.359 or 12.361 since it is rounded in the end). Getting an exact formula will not be easy if it is possible.
The cooldown is very easy to calculate at max(20, energy / 50) seconds.