MaplePrimes - comments on Post, Soccer ball

MaplePrimes - comments on Post, Soccer ball http://www.mapleprimes.com/posts/94930-Soccer-Ball en-us 2026 Maplesoft, A Division of Waterloo Maple Inc. Maplesoft Document System Thu, 11 Jun 2026 09:41:05 GMT Thu, 11 Jun 2026 09:41:05 GMT The latest comments added to the Post, Soccer ball http://www.mapleprimes.com/images/mapleprimeswhite.jpg MaplePrimes - comments on Post, Soccer ball http://www.mapleprimes.com/posts/94930-Soccer-Ball Jabulani http://www.mapleprimes.com/posts/94930-Soccer-Ball?ref=Feed:MaplePrimes:Soccer ball:Comments#comment94932 I'll be impressed if someone can plot one of the actual 2010 World Cup balls: <a href="http://en.wikipedia.org/wiki/Adidas_Jabulani">http://en.wikipedia.org/wiki/Adidas_Jabulani</a>    John The latest comments added to the Post, Soccer ball 94932 Thu, 08 Jul 2010 17:55:55 Z John May John May model the Jabulani http://www.mapleprimes.com/posts/94930-Soccer-Ball?ref=Feed:MaplePrimes:Soccer ball:Comments#comment94935 I'd be really impressed if anyone could model the Jabulani's behaviour in Maple/MapleSim well enough to show the purported instability of that relatively lighter ball at higher speeds/altitude. (It may not be necessary to achieve fluid dynamics simulation for this, if the seam pattern's effect could be combined with oscillating wake driving forces. I don't know.) The latest comments added to the Post, Soccer ball 94935 Thu, 08 Jul 2010 18:08:39 Z pagan pagan I like a challenge http://www.mapleprimes.com/posts/94930-Soccer-Ball?ref=Feed:MaplePrimes:Soccer ball:Comments#comment94938 <a href="http://www.mapleprimes.com/posts/94930-Soccer-Ball#comment94932">@John May</a> : Not all the details, but here's a rough approximation of some of the features. <pre>> with(plots): with(plottools): C[1]:= 1; C[2]:= t -> 0.95 + 0.05*sin(3*t); C[3]:= t -> 0.91 + 0.05*sin(3*t); C[4]:= t -> 0.87 + 0.05*sin(3*t); C[5]:= t -> 0.65 + 0.042*sin(3*t); C[6]:= t -> 0.5 + 0.037*sin(3*t); ts:= [seq(i*2*Pi/50, i=0..50)]: A:= [seq([seq([[C[k](ts[i-1]),ts[i-1]],[C[k](ts[i]),ts[i]], [C[k+1](ts[i]),ts[i]],[C[k+1](ts[i-1]),ts[i-1]]],i=2..51)],k=1..6)]: B:= map(a->map(p -> map(t -> [sin(0.8*t[1])*cos(t[2]),sin(0.8*t[1])*sin(t[2]),cos(0.8*t[1])], p), a),A): S:= sphere([0,0,0],0.99, colour=wheat, style=patchnogrid): P:=display(polygonplot3d(B[1],colour=black), polygonplot3d(B[3],colour=gold, style=patchnogrid), polygonplot3d(B[4],colour=black,style=patchnogrid), polygonplot3d(B[5],colour=black,style=patchnogrid)): display(P,seq(plottools[rotate](P,arccos(-1/3),0,k*2*Pi/3),k=0..2), S,scaling=constrained); <a href="/view.aspx?sf=94938/277820/jabulani.jpg"><img src="/view.aspx?sf=94938/277820/jabulani.jpg" alt=""></a></pre> The latest comments added to the Post, Soccer ball 94938 Thu, 08 Jul 2010 21:40:53 Z Robert Israel Robert Israel @Robert Israel Very nice! http://www.mapleprimes.com/posts/94930-Soccer-Ball?ref=Feed:MaplePrimes:Soccer ball:Comments#comment94973 <a href="http://www.mapleprimes.com/posts/94930-Soccer-Ball#comment94938">@Robert Israel</a> Very nice! The latest comments added to the Post, Soccer ball 94973 Fri, 09 Jul 2010 17:46:23 Z John May John May A very good approximation http://www.mapleprimes.com/posts/94930-Soccer-Ball?ref=Feed:MaplePrimes:Soccer ball:Comments#comment94974 <a href="http://www.mapleprimes.com/posts/94930-Soccer-Ball#comment94938">@Robert Israel</a>: Nice! I'm impressed. The latest comments added to the Post, Soccer ball 94974 Fri, 09 Jul 2010 18:02:32 Z pchin pchin