View source for Talk:Anti-Gravity Tutorial

I'm posting this in it's current form because it took me a lot longer to write than I thought it would, and I don't want to lose all of my work. I would appreciate any ways people could improve it; please go ahead and change anything you can! I'm not exactly a Robocode guru, and there's still stuff that needs to be added to this--[[User:CrazyBassoonist|CrazyBassoonist]] 02:38, 21 January 2010 (UTC)

One quick note, is I'm pretty sure the "check various angles" approach is very much not the traditional anti-grav approach, and is closer to min-risk movements actually. The 'traditional' anti-grav approach is simply summing up a 2d total force vector rather than checking angles. --[[User:Rednaxela|Rednaxela]] 02:48, 21 January 2010 (UTC)

: Yeah, it's actually a little simpler than what you have here. For each enemy, something like:
<pre>
xForce += Math.sin(absBearing + Math.PI) / (distance * distance);
yForce += Math.cos(absBearing + Math.PI) / (distance * distance);
</pre>
: Then just move in the direction of the resulting force. Not to say that checking angles is wrong (or even likely to give a different result), but it's veering into [[Minimum Risk Movement|min risk]] territory, and not traditional AG. --[[User:Voidious|Voidious]] 15:57, 21 January 2010 (UTC)
:: Indeed, like that. In this case, checking angles gives a... similar result, except 1) less precise, and 2) rotates to a sane angle if the forces are *perfectly* blanced, but that's unlikely and normally non-issue anyway. If there are no objections soon I'll modify it to use the vector summing approach. As a side note, I'd also say that using a try/catch instead of an explicit null check is... disagreeable code style. --[[User:Rednaxela|Rednaxela]] 16:17, 21 January 2010 (UTC)

:: Aye. It should be either like that or 
<pre>
xForce -= Math.sin(absBearing) / (distance * distance);
yForce -= Math.cos(absBearing) / (distance * distance);
</pre>
:: And use <code>Math.atan2(xForce, yForce)</code> to get the direction of the result vector. --[[User:Nat|<span style="color:#099;">Nat</span>]] [[User talk:Nat|<span style="color:#0a5;">Pavasant</span>]] 16:31, 21 January 2010 (UTC)

In my thought a 'Tutorial' should involve creating a robot. I'll change it later when I have more time. --[[User:Nat|<span style="color:#099;">Nat</span>]] [[User talk:Nat|<span style="color:#0a5;">Pavasant</span>]] 14:14, 21 January 2010 (UTC)

: I'm not sure everyone agrees (though I think that is a good style). When we discussed tutorial style on [[Category talk:Tutorials]], it seemed most people preferred to have pseudocode tutorials, not the explicit bot building style I use in the [[Wave Surfing Tutorial]]. --[[User:Voidious|Voidious]] 15:22, 21 January 2010 (UTC)

:: I am not really sure, but I for one only think of advanced tutorial at that time of discussion. I myself prefer pseudocode for advanced tutorial, and bot building for basic tutorial. I don't believe pseudocode is suitable in such situation -- it won't make more sense than just literal explanation. But for advanced techniques, sometimes you can't explain it with literal explanation, and giving the code is just spoil, so I prefer pseudocode. Any one agree with me on this? And since this article cover from data gathering, I consider this a 'basic' tutorial. --[[User:Nat|<span style="color:#099;">Nat</span>]] [[User talk:Nat|<span style="color:#0a5;">Pavasant</span>]] 15:46, 21 January 2010 (UTC)

Also: thanks for posting, that was pretty quick. =) --[[User:Voidious|Voidious]] 15:57, 21 January 2010 (UTC)

One note about the enemy tracking this tutorial suggests: The approach it uses only really works when one is very certain that enemies will be scanned in the same order each time around. It can have significant anomalies with a non-spinning radar, and even with a spinning radar the order changing could cause the bot to move oddly every so often. I'd only consider using that type of approach in a highly codesize-restricted bot. Do others approve of changing it to a slightly more advanced system for tracking the enemy points without such issues? :) --[[User:Rednaxela|Rednaxela]] 21:06, 21 January 2010 (UTC)