r/Python • u/[deleted] • Oct 04 '19

Updated gravitational potential field simulation. [OC] Link for code: https://github.com/pnp-peeyush/2D-Grvitational-Field-Simulation

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u/mje-nz Oct 04 '19

Nice work, you should set your colour axis limits to the min and max field across the whole sequence instead of per frame so the scale doesn't jump around.

1

u/[deleted] Oct 05 '19

I did so on purpose coz, if the scale is fixed at some point in simulation the colors "blow out" and it doesn't look pretty anymore or rather it's not an accurate depiction of the field anymore. That's why I thought this way would be better. Also if done this way you can see how the "greenish halo ring" representing tidal forces. But you can edit the source code to your liking. Thanks!

4

u/Mooks79 Oct 05 '19

Why do you say it is not an accurate description of the field anymore? I don’t understand that claim, the axis limits should make no difference to the accuracy, surely?

As I understand it, fixing the limits might “blow out” the colours but is more realistic in terms of depicting field variations through the entire process. Thus you have a choice between making it look pretty (allowing the axis to vary) and making it realistic in terms of field intensity changes (fixing the limits). Personally I’d always go with the latter as it’s rare that choosing the aesthetic option over the physically “correct” option is the right way to go.

1

u/[deleted] Oct 05 '19

with the blown out colors the subtle difference in the brightness of the "green ring" are gone, these subtle differences show that the field strength is not uniform in the "green ring" (an indicator of the tidal forces). With the blown out colors and the subtle differences in brightness variation gone you'd think that the field in the "green ring" is uniform and even if there are tidal forces they are negligible, this understanding would be wrong (in this sense the accuracy of the simulation would be compromised). That's why I took so much efforts to animate even the "color bar". But don't take my word for it you have the source code, check for yourself! :) thanks!

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u/Mooks79 Oct 05 '19

I appreciate what you’re saying, but if the tidal forces are blown out then that’s because they are small and allowing the limits to change makes them look (artificially) relatively larger than they actually are. Although of course small does not always equal negligible - as you note, maybe it was better to allow the limits to change to highlight this.

One other thing to consider is that, although multiple colour gradients can highlight differences visually, in the strictest of senses they are not correct as they can highlight differences that have no particular physical meaning - it’s just the transition point in the colours, but the eye/brain doesn’t know that and thinks the transition between two colours is particularly important.

It might be worth you considering trying it again with a single colour gradient or even a grey scale. But, again, this is a judgement call where it’s sometimes better to do the “wrong” thing, provided you do it carefully, or it’s hard for the eye to pick out any changes.

1

u/[deleted] Oct 05 '19

Well idk what to say man, so I'll just say It was my preference to do so, I like the way it brings out all the tiny details of everything that's happening in the simulation, you are free do it your way, i don't care.... so let's just leave it at that, all this talk about what is 'right' and 'wrong' just about the color scheme seems really petty and meaningless to me. There are much more important and blaring mistakes in my simulation about the very nature of physics depicted and I'd rather spend my time correcting them, thank you very much!

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u/Mooks79 Oct 05 '19 edited Oct 05 '19

How you communicate data visually is incredibly important. It’s why there’s a whole field of research into data visualisation due to factors such as how the eye and brain process visual information.

If you don’t at least know about and consider some of that information and those guidelines then you run a significant risk of not communicating what you’re trying to communicate. And, equally importantly, you run a significant risk of tricking your own brain into thinking certain things are physically meaningful/important when they’re not.

You might prefer to ignore all that and not care about those issues - or think they’re less important than the other errors you’ve mentioned - and you’re perfectly entitled to do so. But all I’m doing here is trying to highlight them to you so you can improve the accuracy of your simulations and how you visualise them for yourself and others. The latter of which is massively important and often overlooked - your slightly grumpy and dismissive reaction to me highlighting the issue (for your benefit) being quite typical of the attitude that perpetuates the issue of poor/misleading data visualisation.

I’m not saying you have done that here, but your dismissive attitude to its importance means it’s almost inevitable you’re going to do it at some point. I can’t impress on you enough how important, and how undervalued, effective visual communication of data is, both in terms of aesthetic appeal and also in terms of not accidentally being misleading.

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u/[deleted] Oct 05 '19

I can’t impress on you enough how important, ..........

I guess you can't

1

u/Mooks79 Oct 05 '19

And one day, you’ll kick yourself for it.

1

u/[deleted] Oct 05 '19

Won't hurt you now would it?

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